Janfu Wireless Bluetooth V4.0+EDR HV-800 Neckband Sport Stereo Universal Headset Headphone for Smartphone (Black) Brand new and high quality. Support Bluetooth V3.0, Bluetooth A2DP and call. Keys: Key(NEXT),Key(PREV), Switch, Multi-function Key. Working current: 25-35mA Bluetooth A2DP Working range: 10m Output power: 2x20mW Frequency range: 2.401-2.480GHz Vibration alert on call, Earphone battery display on smartphone. SNR: S/N95 Charging Time: 2h-3h Talk time: 8-15 hours, play time: 6-10 hours Music Playing Time: up to 10 hours Frequency Response: 20 ~ 20000Hz Compatible with All Bluetooth-enabled smart phones laptops MP3 / 4 Etc.