WIRED TRRS 3.5MM, 2.4G, Bluetooth, and USB 7.1 CONNECTION 50 mm SPEAKER DIAMETER Dimensions of the microphone: 4*1.5 mm Direction of Microphones: Omnidirectional Frequency REACTION 15–30,000 Hz 114 ± 3 DB SPEAKER SENSITIVITY -38±2 DB MICROPHONE SENSITIVITY 64 Ω±15% SPEAKER IMPEDANCE IMPEDANCE MICROPHONE ≤2.2 ΚΩ(ΜAX) 15 M BLUETOOTH RANGE 10 M 2.4G WIRELESS RANGE Battery capacity: 400 MAH; playback time: up to 40 hours; standby time: up to 300 hours Weight: 180±3 G; charging time: approximately two hours