Number of supported wireless devices: max. 30 pcs ; Keyboard included; Wireless: 433 MHz ; Built-in modules: GSM, WiFi ; Main features: Bidirectional communication, Built-in alarm siren ; Frequency range: 433 MHz ; Radio communication range (at open area): max. 30 m ; Detection angle / Detection range: 120 ° / 12 m (max) ; Color: White ;