Sennheiser MKE 400. Connectivity technology: Wired, Connector(s): 3.5 mm, Cable length: 0.2 m. Battery type: AAA, Battery life (max): 300 h, Operating voltage: 1.5 V. Dimensions (WxDxH): 130 x 21 x 62 mm, Weight: 60 g. Frequency response: 40 - 20000 Hz