Sony has produced over five million professional ECM (Electret Condenser Microphones) microphones and the ECM-44 is the affordable, general voice model. It provides good sound quality and is widely used in business presentation systems and TV production. The ECM-44 is available in four versions, featuring different connector types. This model, the ECM-44BC, has a 4-pin locking plug for use with WRT-822 and WRT-8B wireless transmitters.