Model WSG - Wireless Power Failure Sensor
From Wireless Sensors
The WSG Wireless Power Failure sensor is designed to work exclusively with the Sensaphone WSG30. This sensor includes a built-in radio transmitter, two AA alkaline batteries and a wall plug in power supply. The sensor will detect a loss of power at the outlet where the power supply is attached. The two AA alkaline batteries will power the sensor and allow it to transmit alarm information in the event that 120VAC power fails.