Driveway Alarm for Gate Opener Wireless Driveway Alarm (FM131) Keep track of vehicles entering or exiting your property with GTO's Wireless Driveway Alarm. When a vehicle passes the sensor, the receiver emits an audible tone and lets you know someone is there. * Instantly be alerted when someone pulls into or out of your driveway * Functional range of up to 400 ft. * Indoor chime announces visitors or unwelcome guests * Electromagnetic sensor only senses large metal objects avoiding false signals due to animals or children. * Indoor receiver can be mounted on a table or wall. * Easy-to-install and stake is included in kit * Transmitter requires 2 "C" batteries (not included) * Low battery indicator on both the Indoor receiver and transmitter New Advanced Detection Design... * features Sensitivity Adjustment (3´–12´radius) that reduces false signals caused by neighboring traffic. * eliminates false signals due to extreme changes in temperature. * includes adjustable dip switches for “cross talk” protection. * professional grade in-ground electromagnetic sensor detection technology.