This Door and Window Wandering Alert Kit contains a pager and a door/window sensor.The door/window sensor has an open field range of 120 metres and, once triggered, sends an alert to the pager unit, which can be worn on a belt clip or on a lanyard. The pager will then beep and vibrate, although it can be set to vibrate only and there is a choice of high or low beep tone. Up to ten sensors can be used with a single pager unit and batteries to power both the pager (2xAA) and the sensor (1x9v) are included with the kit.