TWS wireless headphones are a type of headphones that connect without a cable not only to the playback device, but also to each other. They allow you to wirelessly listen to music, answer phone calls. The headphones are small, comfortable and reliable. The functions of the headphones are controlled by touch function buttons. The case for the headphones has a built-in battery with a capacity of 200mAh, which allows you to recharge the headphones while traveling, training or on a walk. Bluetooth version: v.5.0. Supported Bluetooth profiles: HSP HFP, A2DP and AVRCP. Bluetooth transmitter power: 3dBm Bluetooth transmitter frequency: 2.402-2.480GHz Range: up to 10 meters. Built-in rechargeable battery: Li-Poly: headphones: 30mAh charging case: 200mAh Usage time (talk time): up to 4 hours Music playback time: up to 3 hours Charging time: about 1 hour Frequency response: 20Hz-20,000Hz Input (charging) voltage: DC 5V 25cm USB C charging cable included