Meters M-Magnetic-BT-EARS-TAN TECHNICAL SPECIFICATIONS Type: Closed, Dynamic Driver: 7mm Power Handling Capacity: 1000mW Impedance: 32 Ohm @ 1Khz Sens: 94dB/mW Frequency Response: 20Hz-20kHz Adaptor: Gold plated Weight: 50gs Output Power: MIN 0.35v MAX 0.5v Distortion: MAX 0.2% Channel Separation: Lch/Rch MIN -60dB MAX-40dB BT Transmission distance: 10-15M Battery Life: Continuous 8hrs - Standby 16.5hrs Max charge current: 200mA