... Smart and good-looking.Wireless burglar alarm system with telephone alarm function DESCRIPTION:DIY, Wireless installation, Easy-to-operated ... indoor: 30~50m, (depend on the surrounding environment and wireless interference)4. Standby current: < 20mA5. Alarm volume: internal ... ° horizontal+60°vertical10. Optional sensor: wire siren, wireless smoke detector, gas leakage detector, vibration sensor, siren ...