Esperanza EH163K Headphones (EH163K)

Bluetooth 3.0
Battery capacity: 300 mAh
Power supply: 5V DC - charging via miniUSB cable
Maximum battery charging time: 3 hours
Maximum talk time: 10 hours
Maximum music playback time: 4 hours
Microphone sensitivity (at 1 kHz): -42 dB
Frequency response: 30-16000 Hz
Sensitivity (at 1 kHz): 105 dB
Resistance: 32 ohms
Real power: 100 mW
Frequency response: 20-20000 Hz
Volume control:  YES
Speaker diameter: 40 mm