Introducing our new Bluetooth V4.1 earphones with an operation range of up to 10 meters and support for HSP, HFP, and AVRCP protocols. These earphones offer a frequency response of 20Hz-20KHz and a sensitivity of 105±3dB, with an impedance of 32Ω. The earphones come with a 3.7V 280mAh rechargeable Li-polymer battery charging box, and each earphone has a 3.7V 40mAh rechargeable Li-polymer battery. With a working time of about 2 hours (depending on the volume), and a standby time of about 120 hours, the earphones can be charged with a Micro USB port. These earphones are compact and lightweight, measuring 2.3 * 2.3 * 1.8cm and weighing 4.6g. The package size is 9.1 * 9.1 * 5.1cm and the package weight is 110g.