The RockBLOCK device is IP68 rated and hosts an Iridium 9602 unit, an antenna and a voltage regulator. The 9602 unit is interfaced with RS-232 using AT commands. Depending on the conditions, the unit can send or receive a message approximately every 40 seconds. The cost is 0.1 to 0.05 GBP per 50-byte message, depending on the bundle that is bought. In addition, there is a 10 GBP line rental per month. The system has a limited bandwidth and is therefore only suitable for simple control monitoring or tracking applications. The maximum package sizes are 340 bytes for sending and 270 bytes for receiving. Although the latency is typically a few seconds, it may be as much as a minute or more.

The 433 MHz Radio Transceiver requires a 12 V input and is interfaced with RS-232 at TTL voltage levels. Device settings can be changed with a set of AT commands, but in operation, the device functions as a transparent serial link. This radio is employed for short-range communication with Level 1 during testing of its functionalities.