Sennheiser PC 121 product# S1-PC121 The PC 121 is an over the ear monaural headset, ideal for inexpensive internet telephony and laptop use. Key Feature Robust microphone for high speech intelligibility Adjustable microphone position and ear clip Wearable over-ear left or right Internet telephony compatible Voice recognition Unique "ear clip design" In-line volume control and microphone mute switch Skype certified Delivery Includes 1 PC 121 2 x 3.5mm stereo jacks for both voice and mic PC socketsli