The 3rd generation in MIP System technology allows you to choose different sounds for different bell pushes and other transmitters with the flick of a switch so you can identify which door or room has been activated. The MIP3 system gives you the ability to link up to 16 devices together. Compatible with previous MIP System generations. 32x High quality true sounds custom-made for the UK market which includes Big Ben Westminster chimes 6x tubular bells 5x ding dongs buzzers festive tunes sound effects and Stop Thief message. The 3rd generation has a huge 200m wireless unobstructed range expandable further by using the MIP Signal Booster accessory. Built-in Lithium-Ion battery for recharging from any USB port.