Aico RadioLINK Series Switched Input Module has been designed to triggers the alarms in a system if an external device is activated, such as a sprinkler system. It is powered by a tamper proof, sealed in lithium cell giving a completely wire free installation with a 10-year life. The unit uses RadioLINK to wirelessly interconnect with the rest of the alarm system. On receiving a volt-free switched hardwired signal, the unit will transmit a RadioLINK alarm signal. The indicator will flash green every 40 seconds to indicate that the lithium cell power supply is healthy. If the Lithium cells are depleted, the indicator will flash amber every 10 seconds and the unit needs replacing.