Model Number: HM-620PHR-#0839 Brand Name: HEIMAN Key Specifications/Special Features: 2017 hot sale 9 V battery 433 Mhz wireless smoke sensorTest by hand, low battery warningHush buttonLow standby current, auto reset, ASIC adoptedAnti-light, mothproof, strong adaptability for circumstanceSMT design, high stabilityWireless interconnection, meets EN14604,UL217 Operating voltage 9V wireless smoke detector static current less than 10uA alarm current less than 15mA Backup Battery 9V battery Sound level ≥85dB/3 meters alarm indication LED flash alarm sound ≥ 85dB/3m operating temperature 40 to 100(4 to 38 humidity 5%-95%RH code form 2262 OR 1527 Detecting area 20 square meters Dimension 128 x 38mm detecting area 20 square meters