Extra-long battery life -- With a built-in 1000mAh lithium polymer battery, Muitune i35-JPO headphones have 120 hours of playtime at 80% volume. With the Type-C charging port, they can be fully charged in three hours and charged from empty in ten minutes to achieve 10 hours of playback. Fine vivid sound -- Hybrid design features a single custom balanced armature driver for each earbud and 10mm neodymium diaphragm delivers powerful bass, vivid and stereo. Aluminum alloy cavity effectively avoids interference with external signal to output stable sound. Ergonomic design -- i35-JPO bluetooth in-ear headphones optimized the angle at which the earbuds enter the ear canal, the lightweight earbud itself weighs less than 5 grams, they can fit almost all outer ear shapes, and three sizes of L, M, S soft caps allow you to wear comfortably for a long time. Bluetooth 5.1 Connection -- Adopts the advanced Bluetooth 5.1 chipset. Muitune i35-JPO supports HFP1.7/ HSP1.2/ A2DP1.3/ AVRCP1.6/ SPP1.2, which greatly improves the transmission speed and provides you with a low-latency listening experience. Fast pairing in less than one second. Easy to use -- i35-JPO blue tooth headphones are compatible with all Bluetooth-enabled devices, such as Android phones, iOS devices, laptops, mp3 and so on. It has a built-in microphone for clear phone calls, and it is also compatible with Siri and Android voice assistant.