The T3-MJ+ is a simple installation requiring a 2-inch round hole. Less than 1.5-inches of under table clearance is required. The built-in, acoustically isolated microphone connector accommodates microphones with 3-pin XLR plugs of a diameter of 1-inch or less and provides superior shock and vibration damping. They are designed to accommodate a wide range of tables and lecterns with up to 21?8-inch thick surfaces. An undertable shroud is provided as part of the assembly. The T3-MJ+1BM or 2BM models feature an internally pre-wired built in mute feature. The right switch, when pressed, will alternate between mute / unmute states. Mute status is provided via the bi-color LED with red indicating mute and green indicating active. Power for this feature is derived from the mixer's phantom power source.