Iwoo Wireless Bluetooth OEM Universal Stereo Headset Headphone Neckband Earbud , Black Brand new and high quality. Support Bluetooth V3.0, Bluetooth A2DP and call. Keys: Key(NEXT),Key(PREV), Switch, Multi-function Key. Charging voltage: Micro USB 5V Working current: 25-35mA Bluetooth A2DP Working range: 10m Output power: 2x20mW Frequency range: 2.401-2.480GHz Distortion factor: 1% Frequency response: 20Hz-20KHz Working Time: Music/ HuaTong state 10 h SNR: S/N95 Charging Time: 2h-3h CSR BC05 stereo Bluetooth chip, which guarantees high fidelity,stable performance and excellent communication effect.