Choose your favorite ring tone according to personal preference Intimate design for your smart life. reasonable size design, optimize the internal structure, which bring you convenience ,beauty and enjoyment. small size which do not take place,plug in anytime to use,easy and convenient. Features: Name: WiFi USB Siren Alarm Material: ABS Power supply: Mini USB, 5V-1A Backup power supply: CR123A x 2 (optional) Sound intensity: 100 dB Wireless Type: 2.4GHz, 1T1R Protocol: IEEE 802.11b/g/n Wireless Range: 45m Operating Temperature: 0¡æ¡« 60¡æ (32°F¡«104°F) Free app: Tuyasmart or Smart Life. Support systems: Android and IOS. Workes with Alexa Echo and google home. Product size(D*W*H): 68x 68x 30mm