... window,public service,bank,toll station intercom.hansfree,with clear voice functionFunctions and Features:1 Full metal jacket,elegance,aesthetic2 ... and squeal problems.4 Adopt high-powered mic,elegant appearance,voice is lifelike,clear;th volume of master station and ... for connecting master station and substation.6 Have output for recording,can connect record equipment external.7 Widely use at any ...