The HT kit consists of one MURS Alertâ„¢ transmitter and one M538-HT hand-held transceiver. This kit is ideal for people that are out and about, such as security guards, sales staff, and outdoorsmen.Features with all optional accessories:Both can be used indoors and outdoors, even during winterHelps monitor your perimeter - The MURS Alert Transmitter (MAT) has a passive infrared (PIR) sensor that detects large animals, vehicles, and people who are 30~80 feet in front of the MATProvides a 2-way conversation - The M538-HT Transceiver receives alert messages from any MURS Alert Transmitter. It can also transmit the message to another MURS unit like the M538-BS Base StationReadily expandable - Dakota Alert doesn't limit you in how many MATs or MURS radios you can add in your wireless communication system. Pair 1, 2 or 4 MURS transmitters with several M538-HT unitsDoesn't require an FCC license - FCC allows the use of Multi-Use Radio Service (MURS) without a license. This VHF (Very High Frequency) radio operates in 151.820~154.600MHz frequencies