This alarm features an 800-meter wireless transmission range with advanced FSK+FHSS technology to reduce interference. It offers a motion detection range of 10 to 15 meters, with adjustable sensitivities to minimize false alarms. The system is expandable to 32 sensors per receiver and supports unlimited receivers, with 35 optional melodies for customization. Price drops from $81.82 to $23.07 w/ free shipping.