Form FactorIn Ear Connectivity TechnologyWireless Wireless Communication TechnologyBluetooth 1. Advanced Bluetooth 5.1: Equipped with latest bluetooth 5.1 technology, the wireless bluetooth earbuds has more stable connection, long transmission range with low power consumption.The bluetooth earphones also support HSP, HFP, A2DP, AVRCP, which greatly improve the transmission speed and providing you with a low-latency listening experience when you listening to music,watch videos or playing games. 2. Superior Clear Call and Immersive Stereo Sound: These wireless ear buds with 13mm speakers and triple-layer composite diaphragms provide powerful bass, stunning treble and clear mids. You can share the earbuds with your friends and families. Each earbud has a build-in microphone for phone calls. CVC noise reduction can make others hear your voice very clearly while phone calls. 3. Portable Charging Case: The charging case allows you to charge the and can be played continuously up to 3 hours on a single charge(About 0.5 hours). With the LED display, you can accurately understand the remaining battery level of earphones and charging case at any time. 4. Ergonomic Design and Easy To Carry: Bluetooth sports earbuds are designed for different ear shapes to ensure a comfortable fit. Charging case is small and can be easily stowed in your pocket. 5. Waterproof Design: These wireless earphones are waterproof, the nano-coating on earbuds surface can prevent water and sweat from penetrating, which can use as sport wireless headsets. You can listen to the music while running, working, reading, sleeping, meeting, etc.