The Clarity AlertMaster AL12 is a visual signal system designed for use by individuals who are deaf or hard of hearing. This product is an accessory for the Clarity AlertMaster AL10 or Clarity AlertMaster AL11 alert system (see separate entries). When connected, it provides flashing lamp and icon notification anywhere within 80 feet of the AlertMaster AL10 and AlertMaster AL11 base units. The system has six indicator lights for six alerting functions: phone, door, clock, sound, alarm, and motion. Display brightness is adjustable and dual power backup keeps the system running when the power is out. It also can be connected to a lamp so the lamp illuminates as an additional visual signal. POWER: Uses standard 120 volt power outlet, and has a rechargeable battery backup. WARRANTY: One year limited warranty.