Power Source: 120Vac 60Hz .5 Amp / 24Vdc 100ma. Battery: 3.7Vdc 2.8Ah lithium ion battery CWSI P/N BA-3.7V-2.8AH supervised Operating Temperature: 32 to 120 degrees F Operating Humidity: 85% non-condensing Transceiver Operating Frequency: 900 MHz band Signal to Noise Ratio: Minimum Signal -100.2dBM Maximum Noise -115.3dBM Antenna Type: Omni/Yagi Transmission Format: Frequency Hopping - Spread Spectrum. Relays dry contact rating: 30Vdc 5A non-power limited or 30Vdc 3.25A power limited Dimensions: 7''Â� high, 8''Â� wide, 2 Â¼''Â� deep Enclosure: Powder coated steel Weight: 1 Lbs. SR-5 Ratings @ 3.7 Vdc: Standby 50ma. Alarm 400ma. @ 24Vdc Standby 17ma. Alarm 85ma.