Macally Cordless Stereo Headset for iPod nano. Ear coupling: supraaural, Headphone frequency: 20 - 23000 Hz, Headphone sensitivity: 105 dB. Connectivity technology: Wireless, Connector(s): 3.5mm. Dimensions (WxDxH): 55.9 x 33 x 76.2 mm, Weight: 172 g