Plug and Play Set: including microphone and connection cable nBuilt in speaker: for near field reinforcement nIntuitive User Interface: concentrate on the real things n2 ports of headphone sockets enable the use for 2 persons n nThe CS3 DU (Delegate Unit) is a basic microphone unit for CS3 conference system. It contains a speak button, a built-in loudspeaker and two headphone jacks as well as a connector to other microphone units. Users can listen to conference speech through built-in speaker or headphones. n nThe station has a detachable microphone that comes in 2 lengths – CS321 condenser, cardioid, 30cm long, and CS521 condenser, cardioid, 50cm long.