Audio substation for SMC intercom system. Stainless steel front panel and metallic call button. Flush mounting. Includes high sensitivity omnidirectional microphone and 4 W mylar speaker moisture resistant. Supplied with compact metal housing, internal metal grill for speaker vandal proof protection and special allen type screws to secure the front panel. Connection to remote control unit (UR or UR-4). Dimensions 128 x 110 x 5 mm.