... home, business store, public plaza security and so on. The control panel is with strong function. Description:DIY, Wireless ... Police Dept..all industrial security and protection system. Specification:Wireless frequency: two option: 433MHz or 315MHzAn adaptor: ... indoor: 30~50m, (depend on the surrounding environment and wireless interference).Standby current: < 20mAAlarm volume: internal :95dB, external ...