Wireless Bluetooth Sports Neckband Headset Headphones Earphones for Cellphones Black/White Main IC: ISSC V3.0+EDR, Support two Bluetooth products linking at the same time Support Bluetooth standard: HSP, HFP, A2DP, AVRCP Frequency range: 2.401-2.480GHz ;Frequency response: 20Hz-20KHz Bluetooth Working range: 10M Working voltage:3.7V ;Working current: 30mA