SABRE Wireless Home Security Door Window Burglar Alarm with Magnetic Sensor for use with SABRE WP-100 - DIY EASY to Install MAXIMUM SECURITY  fortify your existing Wireless Home Alarm System with this additional door/window sensor for greater coverage USER-FRIENDLY & SECURES LARGE AREAS  alerts the home alarm system when a door or window is opened; sensors can be placed up to 500 feet (150M) from main control panel VERSATILE & CONSUMER PREFERRED  ideal for use on windows and doors around the home including garages, cabinets, sheds, attics, side doors, and even freezers; superior to other home security products, this premium white sensor looks great inside your home EASY INSTALLATION  no wiring needed, plus sensors mount on either side (requires 2xAAA batteries, not included) EXTRA LEVEL OF SECURITY  provides battery status update with low battery indicator