TDK WR-700. Ear coupling: circumaural, Headphone frequency: 20 - 20000 Hz, Headphone sensitivity: 106 dB. Connectivity technology: Wireless, Headphone connectivity: 3.5 mm, Wireless technology: RF. Battery life (max): 30 h, Battery type: AAA. Package dimensions (WxDxH): 207 x 205 x 75 mm, Package weight: 564 g. Maximum input power: 0.3 W