The MX10 Universal Amplifier connects your telephone and PC or external audio device to a Plantronics® headset and provides control of the sound through your headset. The MX10 includes near-universal compatibility with single- and multi-line telephones. A Quick Disconnect™ connector allows you to walk away from your desk without removing the headset or disconnecting the call. Product Features: – Switch easily between the phone and the PC or audio device. – Switch between headset and handset with a single button. – Near-universal compatibility with single- and multi-line telephones. – Compatible with most sound cards.