If your MURS vehicle sensor probe has been damaged or worn out, you can replace it with the Dakota Alert MURS Wireless Vehicle Detection Probe Sensor (250 ft.). The probe works with either the base station MURS transceiver (M538-BS) or the handheld MURS transceiver (M538-HT) to detect passing vehicles up to 12 feet away and alert you through the transceiver. The sensor is designed to be buried parallel to the driveway and wired to the transmitter box with the included 250-foot cable. Powered by six AA alkaline batteries. NOTE: Requires either the base station MURS transceiver (M538-BS) or the handheld MURS transceiver (M538-HT).