Jack plug 3.5mm stereoHeadphoneNominal impedance 32 OhmEar coupling monauralCable length 3 mFrequency response (headphones) 50.....15000 HzSound pressure level (SPL) 114 dB(SPL)MicrophoneFrequency response 80.....15000 HzPick up pattern Omni-directionalThe PC 121 is an over the ear monaural headset, ideal for inexpensive internet telephony and laptop use.FeaturesRobust microphone for high speech intelligibilityAdjustable microphone position and ear clipWearable over-ear left or rightInternet telephony compatibleVoice recognitionUnique "ear clip design"In-line volume control and microphone mute switchSkype certifiedDelivery Includes1 PC 1212 x 3.5mm stereo jacks for both voice and mic PC sockets