WireFree Sensor Assemblies OI-6900 Explosion Proof Dual Battery Powered WireFree Sensor Assembly OI-6900 Non-Explosion Proof Dual Battery Powered WireFree Sensor Assembly OI-6940 Notis Quad OI-6940 Non-Explosion Proof Notis Quad OI-6940 ST WireFree Monitors OI-7010 Hybrid Monitor with Four Relays and RS-485 Modbus Output OI-7032 Hybrid Data-Logging Monitor OI-9850 The Interface OI-7530 Non-Explosion Proof Relayer with Three Relays OI-7530 Explosion Proof Relayer with Three Relays Other WireFree Products OI-5950 Explosion Proof Battery Powered Dual Switch State Transmitter OI-9100 WireFree Signal Strength View OI-501-7 Hazardous Location Remote Kit