Model Number: SMOKE : YG---05 Brand Name: Wolf-Guard Key Specifications/Special Features: *Wireless Smoke Detector*Photoelectric sensor, with high sensitivity&stabelity and low power consumption. *9V battery operated (included);*Check battery voltage every one minute. When it's less than 6.8V, it will make sound to alert.*Siren volume: 85DBWe also have stand alone GSM Smoke detector for sales. Welcome to purchase for more.my skype is: shirleykappar