Remax RB-S18 Magnetic Bluetooth Earphone comes with Bluetooth Version: V4.2, Frequency: 2.402-2.480GHz. This earphone will give you Working Time: about 4 hours, Charging Time: about 2 hours, Standby Time: about 80 hours. It is featured with 10m Transmission Distance, Class 2 Transmission Power, 5V/50mA Charging Voltage, ≥90dB SNR. According to the sound structure of the careful debugging, It filter out the human ear fatigue noise and be amended, High and low frequency distribution. In this headphone, the transition of the band is naturally smooth,comfortable and no burr, whether listening to music or call are more clear. This Earphone has no warranty.