The GEMC-WL-SMK is a high-quality photoelectric smoke detector with built-in supervised digitallycoded radio transmitter. It is compatible with Napco's GEMC-RECV supervised receivers that monitor alarms, restores, low battery, tamper and status. During normal operation, when unit is in standby mode and is within proper sensitivity limits, the green LED on the GEMC-WL-SMK flashes once every 10 seconds. As soon as smoke is detected, the GEMC-WL-SMK sounds a local alarm and the transmitter sends an alarm signal to the supervised receiver (Operating Frequency: 319.5MHz). The alarm signal is repeated as long as smoke is still present. A restore report is sent when the smoke detection chamber clears. Supervision status reports are sent from the GEMC-WL-SMK every hour. The GEMC-WL-HEAT is a high-quality wireless 135°F (57°C) fixed-temperature heat detector with Rate of Rise. It is compatible with Napco's GEM-RECV supervised receivers that monitor alarms, restores, low battery, tamper and status. The GEM-WL-HEAT incorporates circuitry that will transmit an alarm signal upon an alarm condition, generate an hourly supervision test signal to the receiver and also monitor and annunciate low battery. Coding switches are not required or used in the GEMC-WL-HEAT. Each transmitter is assigned a unique identification code number at the factory. The transmitters are powered by one 3V Lithium battery (supplied) that can power the unit for up to two years.