Features: Adopt BT5.1 chip, signal transmission is high-speed and stable, providing high-quality sound and quality, a stable connection within 10 meters. Switching between single or double ears modes. In permeable mode, you can hear external sounds without taking off the headset when making a call or listening to music. Intelligent touch control, no need to press, comfortable ear-in design, fits the ear outline. Built-in high-definition microphone, ANC intelligent noise reduction, high-quality calls, high-definition call noise reduction technology. With a 300mAh charging compartment, long battery life, longer music playing time, headset fully charged for 1 hour, can be used for 4-5 hours. Specifications: BT Version: BT5.1 Transmitting Distance: 10m/33ft (no obstacle) Frequency Range: 20-20000Hz Charging Box Capacity: 3.7V 300mAh Earphone Battery Capacity: 2 * 3.7V 40mAh Charging Time: about 1 hour WorkTime: 4 hours Material: ABS Color: Black Package Size: 10.5*8.3*3.7cm / 4.13*3.27*1.46in Package Weight: 68g / 2.40oz Package list: 1 * Pair of Earbuds 1 * Charging Box 1 * Charging Cable 1 * User Manual