FCC/IC/ETSI/CE approved RF modules for up to 256 remote sensor-transmitters & up to 96 Remote Relay Modules.- Minimal installation cost - virtually no field wiring required. Continuous 2 year Battery-powered sensor operation with self diagnostics. Sensors are also available for 24V AC operation. Relay outputs from the Control Panel or from Remote Wireless Relay Modules. "Plug-and-play".