MURS 4-Mile Range Wireless Intercom: Hand Held Radio and Base Station Radio is portable, take with you anywhere within range. Base has a 12V relay. No learning required, just turn to the desired channel; 5 channels and 38 sub-channels. Seamlessly integrates with our MURS Hand Held Radios, PA, Call Boxes and Driveway Alarms. No limit to the number of intercoms or radios, making the creation of a custom network easy