Features: 1. Integrated BT 5.1 chip, offers fast speed, stable connection, allows transmission of 10 m without obstacle. 2. Compatible with mainstream devices, suitable for multi-platform, multi-system, and major brand mobile phones. 3. Effectively block external noise, and real-time audio calibration can maintain a high-quality listening experience. 4. The mini in-ear headsets are ergonomically designed to fit each ear perfectly. Perfect for exercise, running, sports and games. 5. LED digital display shows the remaining battery power of the cordless headset clearly, then you have the charge status of your device at all times. Notice: Actual color may be slightly different from the image due to different monitor and light effect. Please allow 1-3cm deviation due to manual measurement. Description: Bluetooth-Compatible version: V5.1 Supported protocols: A2DP/AVCTP/AVDCP/HFP/SPP/SMP/ATT/GAP/GATT/RFCOMM/SDP/12CAP Talk time: about 4 hours (single use of headset) Cumulative battery life: about 48 hours (used with the charging compartment) Operating temperature: -10C-40C Charging input: 5V1A Charging time of charging box: 1-2 hours