Sabre's Window/Door Alarm may be used as a door alarm sensor, an alarm window sensor or by augmenting your existing system. Sabre's Window or Door alarm alerts the home alarm system when a door or window is opened. Sensors can be placed up to 500 feet (150 m) from main control panel, no wiring is needed plus sensors mount on either side (requires 2-AAA batteries, not included) and provides battery status update with low battery indicator. Ideal for use on windows and doors around the home, including garages, cabinets and sheds as well as attics, side doors and even freezers.