The Shure The MX391WC is a supercardioid miniature white condenser boundary microphone with an in-line preamp and a 12 foot (4 meter) attached cable that terminates to a 4-pin mini xlr connector. Equipped with features like programmable, silent membrane switches, logic inputs and outputs, and LED indicators, Microflex™ Boundary Microphones are the high-quality solution for a range of applications such as altars, boardrooms and distance learning centers. Every Microflex Boundary microphone features a choice of interchangeable condenser cartridges.