Wireless Smoke Detector HM100A-YGWireless Smoke Detector HM100A-YG PC for Series HM2088, HM2098 & HM3088.Operating Voltage : 9V DCDetecting Range : 8 to 12 metersWarm-up Time : 120 secondsOperating Frequency : 315 MHz 433MHzOperating Temperature : 4C to +50CDimension (DxH) : 53 x 35 mm.Description FunctionsWhen smoke is detected within the covered range, the Sensor will send a signal to the Control Panel to trigger the Alarm. When the Sensor emits short "beeps" at every minute, it signals that the battery is weak. Change immediately. Estimated life span of battery is approx 12 months depending on usage.Warranty: 1 year against manufacturing defects.