Attractive and well contured housing for superior appearance. Priority Functon to override all delegate unit (in CHAIRMAN FREE mode.) Multi colour Display to show the misrophone ID. battery Level, Room ID etc. Microphone Indicator ring LED. Individual volume buttons to adjust the microphone pickup level. Power supply 3.7v/1450mAh rechargeable battery. chairman unit can be used with LGM-20 or SGM-40 microphone.