The Plantronics 85638-01 M12 Cable Adapter is an essential part of a headset-enabled phone set-up. It is compatible with a variety of systems including the M12 the MX10 SP and others. Working as both an extension and an amplifier this component connects these models to NEC or equivalent phone systems. It is quick and easy to connect to the expansion module enabling correct and reliable headset operation. This Plantronics cable adapter is useful in a variety of workplace environments.