Product Description: SR-108 Main features: 1.. Working voltage: 24V 2.Alarm current: 30mA 3.Operating temperature: -10 ~ 60 4.Sound pressure: 85dB (It can be customized) 5.Alarm mode: independent alarm 6.Back-up battery: need OEM 7.Environmental humidity: â?¤ 95% RH 8.Product Size: 127 * 121 * 101mm