ENC Environmental Noise Cancellation & Crystal-Clear Calls: featuring 8.0mm diameter speaker with crystal clear treble, 4 microphones deliver up to 3 times clearer calls than other truly wireless earbuds,reproducing your music vividly. Stereo & Immersive Sound Quality: Adopt the advanced Bluetooth 5.3 technology. With 3D immersive stereo surround sound, high bass balance, strong signal, smooth connection when talking and listening to music, support HSP, HFP, A2DP, AVRCP, which greatly improve the transmission speed and providing you with a low-latency listening experience. Tiny Size and Secure Fit Design: Mini and comfortable design earbuds, secure fit all shape of ears, so 100% safe and stable while running, biking, training, jogging, hiking, exercising gym exercise and so on. Long Endurance: TOZO T9 earbuds lasts 9 hours for normal use (60% volume) on a single charge. IPX7 Waterproof