Easily links / extends any existing MIP/2/3 System Door chime system. MIP System 3 uses 3rd generation technology and allows you to choose different melodies for different bell pushes and transmitters with the flick of a switch. Ideal for home, Garden, sheds, warehouses, restaurants, hotels, offices etc, Extra bell pushes, chimes, signal boosters and motion sensors available from our store separately. 200M range (unobstructed), choice of 32 melodies (listed in description below), variable volume control, current melody playback function and a useful flashing strobe light indicator. Purchase and link up to 16 different accessories (bell push, receiver, magnetic sensor, PIR motion sensor, etc.) you can create the perfect alert system for your home or business. . Chime size: 9.5cm x 5.5cm, Chime Unit plugs into any standard UK wall socket.,1 x 12 volt battery (Type is called MN21, A23 or LRV08 battery) for the door push is included. .