Zoom Bluetooth Stereo Headphones & USB Bundle for Skype. Ear coupling: supraaural. Connectivity technology: Wireless, Wireless technology: Bluetooth, Wireless range: 100 m. Battery life (max): 12 h, Battery technology: Lithium-Ion (Li-Ion). Microphone sensitivity: 102 dB, Playtime internal battery: 12 h, Microphone input impedance: 32 Ом