Zoom Bluetooth Wireless Stereo Headphones/Headset. Ear coupling: supraaural, Headphone frequency: 25 - 16000 Hz, Headphone sensitivity: 102 dB. Connectivity technology: Wireless, Wireless technology: Bluetooth, Wireless range: 20, 100 m. Dimensions (WxDxH): 145 x 50 x 135 mm. Battery life (max): 12 h, Battery technology: Lithium-Ion (Li-Ion), Battery type: Re-chargeable