vhfBridge is a module for connecting Ajax security systems to third-party VHF transmitters. It provides 8 transistor outputs for connection to third-party VHF transmitters. The device is powered from 100–240 V mains and can be operated from a 12 V⎓ backup battery. vhfBridge operates as part of the Ajax security system and connects to the hub via the Jeweller secure radio communication protocol. The hub communication range is up to 1,800m without obstacles. Supplied in two configurations: with a casing and without it.