Lifemax Wireless Home Panic Safety Alarm Emergency Alert System with 2 Pendants Main unit receives and recognises who is calling and the urgency from different sound and coloured light signals Caller can choose between a regular call signal or a panic alarm - Quick reset button on main unit to cancel the call or alarm Main unit can be battery or mains operated for use in any location - Optional 6v mains adapter (order item 672.1) Low battery warning signal - Each transmitter uses 1 x 23A 12v battery (included) Range up to 30 metres - The receiver unit is powered by 4 x AA batteries (not included)