Features: brand new and high quality Bluetooth-compatible provides instant pairing and stable transmission without interruptions. for most band bluetooth-compatible devices. Hang neck type earphone and easy to carry. Ergonomic design,fits the neck and shoulder, even worn for a long for time, it will not compress the neck and shoulders. It can also bring a pleasant and comfortable music experience during exercise. The earphone has a built-in Ntc temperature detection circuit to detect the temperature of the lithium battery to prevent damage to the battery due to high or low temperature during charging. The product has an overvoltage for protection function, but the working voltage is within the range of 3.0-4.2V. When the power is low or has not been used for a long for time, the product should be charged in for time to prevent the product from malfunction or battery damage; The bluetooth-compatible wireless signal will be blocked and absorbed by surrounding objects. Try to place it in an obstacle-free position with the bluetooth-compatible connected device during use, so that you can enjoy better sound; Please keep the product away from water or other liquids to avoid damage to the product; Specifications: Material:Silicone Color:Black Bluetooth-compatible Version: V 5.0 Operating range: About 33 feet (10 meters accessibility) Headset Battery Capacity: 220mAh Headphone Jack:Micro-USB; Transmission Power:CLASS2 Frequency Range:2.4GHz-2.480GHz External Power Supply Voltage:DC 5V Working Current:About 16mA Charging Current:180mA Cable Length:200mm/7.87in Package Includes: 1xBluetooth-compatible Earphone 1x Charging Cable note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.