Short answer
An electronic seal is a locking device that records each lock and unlock as a timestamped, located and attributed event, usually reporting over a cellular link. Unlike a mechanical seal, which proves tampering only when inspected, it produces a continuous record, but it does not physically resist force any better.
Key takeaways
- An electronic seal records events; a mechanical seal under ISO 17712 provides a graded physical barrier.
- The two are not competitors, on high-value movements the strongest configuration uses both.
- Master/slave architecture lets one connected unit cover several doors without a SIM in each.
- The decisive technical property is what happens to events during a loss of connectivity.
- It improves detection and evidence; it does not prevent forced entry or coercion.
01The short definition
An electronic seal, often called an e-seal, e-lock or smart lock, is a device that secures an access point and records every locking and unlocking operation as a structured event. Each event carries a time, a position and the identity of whatever authorised it.
The recording is the defining feature, not the locking. Many mechanical devices lock at least as securely; almost none of them produce a record. An electronic seal is therefore better understood as a connected telemetry device that happens to include a locking mechanism than as a lock with a radio attached.
The practical consequence is that the questions worth asking when buying one are mostly data questions: what events are generated, where they are stored, how they behave when connectivity is lost, and who can retrieve them afterwards. The mechanical specification matters, but it is rarely what separates one product from another.
02How it differs from a mechanical seal
A mechanical seal is a one-time device carrying a unique number, which cannot be opened and reclosed without visible damage. Its guarantee is narrow and genuine: an intact seal whose number matches the shipping document means the door was not opened in between.
ISO 17712:2013 formalises this for freight containers, classifying mechanical seals into three grades by barrier strength, "I" for indicative, "S" for security and "H" for high security, with the classification validated by an independent laboratory accredited to ISO/IEC 17025.
An electronic seal is not graded under that scheme, because it is a different category of device answering a different question. The mechanical seal answers "was this opened," retrospectively and only on inspection. The electronic seal answers "when, where and by whom," continuously and without anyone having to look.
03What is inside one
A connected electronic seal contains four subsystems: a locking mechanism, a positioning receiver, a radio for reporting, and a power source large enough to run the other three for a useful period. Everything else is packaging and firmware.
The Jointech JT701 illustrates a typical set. It carries IP67 ingress protection, GSM/3G connectivity with dual SIM, GPS accuracy quoted at 2.5 m CEP, a 15,000 mAh lithium-ion battery charged over micro-USB, and an operating range of −20 to +70 °C.
Note the balance of that specification. One line concerns locking; the rest concerns acquiring a position, holding a network session, surviving heat and dust, and running for weeks between charges. That is where the engineering difficulty and most of the failure modes live.
04Master and slave configurations
Fitting a full cellular and GPS stack into every lock is wasteful when a vehicle carries several doors that travel together, so most product families split the roles.
The Jointech JT709ex is built as a field lock: it carries no GPS and no cellular connection of its own, links to a JT701 master over Bluetooth or LoRa at up to 1 km in open area, is unlocked remotely through that master, and is quoted at up to three years of standby life precisely because it is not maintaining a radio session.
The trade-off is a single point of dependency. Every slave is only as reachable as its master, so one master failure silences the whole set rather than one door. That is usually worth it for removing a SIM, a subscription and a charging routine from each additional lock, but it should be chosen knowingly.
05The events an electronic seal produces
The event set is what you are actually buying, and it divides into operations and attacks. Operations are locking and unlocking, each carrying the credential that authorised them. Attacks are attempts to defeat the device.
The JT701 detects rope cut, cover opening and vibration, and publishes alert types covering rope cut, back cover, geo-fence and low battery. The JT709ex reports tamper, use of its mechanical emergency key, and shackle cut.
Those describe genuinely different intentions: severing the securing element to remove the lock, opening the housing to reach the electronics and stop it reporting, and operating the lock through a legitimate override at a possibly illegitimate moment. A product that reports only open and closed states is missing most of the security value.
06How authentication works
A physical key works for anyone holding it and leaves no record. Replacing it changes both properties, and the method chosen determines how much assurance the resulting record carries.
The JT701 supports an RFID card, a password, and a remote command issued from the platform. The JT709ex adds a mechanical emergency key alongside Bluetooth and RFID. These are not equivalent: a remote command is authorised centrally and attributable to an operator identity, while a card is only as controlled as the process issuing cards.
The design decision that matters is which method is the default. Operations that rely mainly on remote unlocking produce the strongest audit trail, because the decision to open is made by someone not standing at the container and the reason can be recorded before the door moves.
07Connectivity, and the question that decides products
The single most revealing question about an electronic seal is what happens to events when the device loses connectivity for an hour or a day. It is rarely on the specification sheet and it separates products more sharply than anything that is.
A sound answer describes three things: where events are stored while the link is down, how their order is preserved, and how they are resynchronised when it returns. A weak answer describes the radio reconnecting, which says nothing about whether the events survived.
This matters because coverage gaps are not randomly distributed. They cluster in isolated places, which is exactly where the events an operator most wants to see are most likely to occur. A device that only transmits live will show a flat timeline across precisely the interval an attacker would choose.
08Power and the charging problem
Charging is the operational burden organisations most consistently fail to plan for, because the process being replaced has none at all. A mechanical seal needs no power; a connected lock needs a routine that did not previously exist.
Capacity follows role. The JT701 master carries a 15,000 mAh lithium-ion battery, sized for a unit maintaining a cellular session and a GPS fix. The JT709ex slave, running neither, is quoted at up to three years of standby life.
The failure mode is worth naming: a lock that runs flat mid-route is a security gap that presents as silence, and the usual cause is not battery quality but an unassigned task. Deciding where charging happens and who is accountable, before deployment, prevents most of it.
09Environmental ratings and what they mean
Ingress protection is expressed under IEC 60529 as a two-digit code. Both locks discussed here carry IP67, where the 6 means dust-tight with no ingress of dust and the 7 means the enclosure withstands temporary immersion up to 1 m for 30 minutes.
That is the appropriate rating for an exposed road vehicle. A higher figure is not automatically better, IP69K, for instance, describes resistance to high-pressure, high-temperature washdown, which matters where equipment is pressure-cleaned and is irrelevant where it is not.
Thermal envelopes are narrower than for fixed equipment: the JT701 is rated −20 to +70 °C and the JT709ex −20 to +60 °C, against −40 to +85 °C typical of fixed fuel sensors. A device on a sun-facing steel door is not at air temperature, so the margin is smaller than the number suggests.
10Positioning, and what it can be relied on for
The JT701 quotes GPS accuracy of 2.5 m CEP, meaning half of position fixes fall within 2.5 metres of the true location. That is more than adequate for the questions a seal is asked, and it is worth being explicit about which questions those are.
It reliably answers whether an opening happened at a scheduled site or elsewhere, how long a vehicle was stationary before a door moved, and whether a route matched the plan. All resolve at tens of metres, so the difference between 2.5 m and 5 m changes nothing.
It degrades where containers spend much of their time, inside warehouses, under gantries, between stacked containers. Position should therefore be read as context attached to an event rather than as an authoritative location at every instant, and geofences should be sized with margin rather than drawn tightly.
11Where an electronic seal is the wrong choice
On short, single-leg, high-volume movements where cargo is not individually valuable, a graded mechanical seal usually wins on economics alone. It costs a small fraction of a connected unit, needs no charging, no SIM and no subscription, and cannot be defeated by a flat battery.
It also wins where the requirement is purely evidentiary. If the purpose of sealing is to support a claim rather than to enable intervention, an ISO 17712 graded, third-party-tested seal already supplies the proof, and the extra data an electronic seal gathers would never be acted upon.
And it wins wherever no one is available to respond during the journey. The entire advantage of a connected device is the possibility of acting before arrival; an organisation that cannot staff that should buy the simpler device and spend the difference on process.
12Using both together
On high-value movements the strongest configuration is both devices rather than a choice between them. The mechanical seal supplies the graded, independently tested physical barrier and the number recorded on the shipping document; the electronic unit supplies the timeline.
This also covers each device’s weakness. If the electronic unit loses power or coverage mid-route, the mechanical seal still delivers the retrospective proof a claim needs. If the mechanical seal is defeated and counterfeited, the electronic log shows a door event the paperwork does not.
The combined cost is not double, because the mechanical seal is by a wide margin the cheaper component. On a lane where a single loss exceeds the annual monitoring cost, running both in parallel is the rational default rather than an extravagance.
13What it does not do
An electronic seal raises the difficulty and the visibility of unauthorised access. It does not make a container impregnable, and it should never be sold as preventing hijacking.
A determined attacker with time, tools or coercion can defeat a physical locking mechanism, and no device on the market changes that. What changes is that the attempt generates a located, timestamped event instead of being discovered at delivery, an improvement in detection and evidence, not a prevention guarantee.
It also does not replace procedure. Route planning, driver vetting, stop discipline and the response process behind the alerts do most of the protective work, and a device deployed without them produces an unusually detailed record of a loss nobody prevented. That is worth stating in an internal security policy as plainly as in a purchase decision, so nobody downstream inherits an expectation the equipment was never able to meet.
14The vocabulary you will meet
Terminology in this market is inconsistent, and the same device is sold under several names. E-seal, e-lock, smart lock, GPS padlock and electronic seal are used more or less interchangeably, so the label tells you little about capability.
Some distinctions do carry meaning. "Master" and "slave" describe whether a unit connects independently or reports through another. "Bolt seal" and "cable seal" describe mechanical form factors classified under ISO 17712. "Geofence" describes a defined area against which position events are evaluated, and "CEP" is a positioning accuracy measure, 2.5 m CEP means half of fixes fall within that radius.
When comparing products, ignore the marketing category and compare the event set, the connectivity behaviour, the authentication methods and the environmental ratings. Those four determine what the device will actually do on your routes.
15Where ENTEK.AI fits
ENTEK.AI does not manufacture locks. The device specifications quoted in this guide are the manufacturer’s published figures, attributed to the manufacturer rather than presented as ENTEK measurements.
What the platform contributes is context. On the Smart Lock solution, each lock event is recorded with its time and position, on a geofenced trip that shows arrival and departure at each stop, so a door event can be read against the trip it belongs to rather than arriving as an isolated notification.
The Smart Lock module sits in the same system as fuel monitoring and fleet tracking, so lock events and fuel readings for the same vehicle can be reviewed side by side.
| Property | Mechanical seal (ISO 17712) | Electronic seal | Both |
|---|---|---|---|
| Independently graded barrier | Yes, I, S or H | Not classified under ISO 17712 | Yes |
| Proves an opening occurred | On inspection | As it happens | Both paths |
| Records time, place and identity | No | Yes | Yes |
| Needs power | No | Yes | Partly |
| Needs connectivity | No | Yes, with local buffering | Partly |
| Enables mid-journey intervention | No | Only with a staffed response | Yes |
| Cost per movement | Low | Materially higher | Slightly above electronic alone |
Figures and sources
- ISO 17712 mechanical seal classes by barrier strength: I (indicative), S (security), H (high security) (Source: ISO 17712:2013, Freight containers, mechanical seals, as of 2026-08-30)
- Accreditation required of the laboratory validating a seal classification: ISO/IEC 17025 accredited independent laboratory (Source: U.S. Customs and Border Protection, ISO 17712 high security seals bulletin, as of 2026-08-30)
- Jointech JT701 ingress protection rating: IP67 (Source: ENTEK.AI product specification, Jointech JT701, as of 2026-08-30)
- Jointech JT701 cellular connectivity: GSM / 3G, dual SIM (Source: ENTEK.AI product specification, Jointech JT701, as of 2026-08-30)
- Jointech JT701 quoted GPS accuracy: 2.5 m CEP (Source: ENTEK.AI product specification, Jointech JT701, as of 2026-08-30)
- Jointech JT701 battery capacity: 15,000 mAh Li-ion (Source: ENTEK.AI product specification, Jointech JT701, as of 2026-08-30)
- Jointech JT701 operating temperature range: −20 to +70 °C (Source: ENTEK.AI product specification, Jointech JT701, as of 2026-08-30)
- Jointech JT701 unlock methods: RFID card, password, remote command (Source: ENTEK.AI product specification, Jointech JT701, as of 2026-08-30)
- Jointech JT701 tamper conditions detected: rope cut, cover open, vibration (Source: ENTEK.AI product specification, Jointech JT701, as of 2026-08-30)
- Jointech JT709ex operating temperature range: −20 to +60 °C (Source: ENTEK.AI product specification, Jointech JT709ex, as of 2026-08-30)
- Jointech JT709ex quoted standby life: up to 3 years (Source: ENTEK.AI product specification, Jointech JT709ex, as of 2026-08-30)
- Jointech JT709ex link to its master, and range: Bluetooth / LoRa, up to 1 km (open area) (Source: ENTEK.AI product specification, Jointech JT709ex, as of 2026-08-30)
- Jointech JT709ex alert types: tamper, mechanical key used, shackle cut (Source: ENTEK.AI product specification, Jointech JT709ex, as of 2026-08-30)
- IP67, first digit: protection against solid foreign objects: dust-tight (no ingress of dust) (Source: IEC 60529, Degrees of protection provided by enclosures (IP Code), as of 2026-08-30)
- IP67, second digit: protection against temporary immersion: immersion up to 1 m for 30 minutes (Source: IEC 60529, Degrees of protection provided by enclosures (IP Code), as of 2026-08-30)
Questions
What is an electronic seal in one sentence?
A device that secures an access point and records every locking and unlocking as a structured event carrying a time, a position and the identity that authorised it, usually reporting over a cellular link. The recording, not the locking, is what defines it.
Is an electronic seal certified under ISO 17712?
No. ISO 17712 classifies mechanical seals for freight containers into indicative, security and high security grades, validated by an ISO/IEC 17025 accredited laboratory. An electronic lock is a different device category and is not graded under that scheme, which is one reason many operators run both.
Do I need a SIM card in every lock?
No. In a master/slave configuration only the master connects; field locks such as the JT709ex carry no cellular or GPS of their own, link to the master over Bluetooth or LoRa at up to 1 km in open area, and are quoted at up to three years standby. The trade-off is that a master failure silences the whole set.
Does an electronic seal prevent theft?
It deters opportunistic access and documents attempts, but it does not resist determined force or coercion and should never be sold as preventing hijacking. The improvement is in detection and evidence: an attempt becomes a located, timestamped event rather than a discovery at delivery.
What single question separates good products from weak ones?
What happens to events when the device loses connectivity for an hour or a day. A good answer names where events are stored, how their order is preserved and how they resynchronise. A weak one describes the radio reconnecting, which says nothing about whether the events survived.