KZ Waterproof High Fidelity Bluetooth Upgrade Cable for KZ ZST ZS10 ES4 ES3 ZSR Earphones(Black) 1. Adopt CVC 4.0 voice call noise reduction technology, which provides advanced audio enhancement and environmental noise suppression, which solves the interference of environmental noise during the call and provides better voice call quality. 2. Qualcomm CSR8645 Bluetooth chip, with 3 seconds of fast connection, excellent reconnection speed and stronger signal anti-interference ability. 3. Bluetooth 4.2 with EDR Bluetooth enhanced rate, greatly improving the data transmission rate of Bluetooth technology, which is three times that of ordinary Bluetooth. Let Bluetooth transfer faster, transfer more stable, more efficient, and lower power consumption. 4. AAC-LC encoding technology, compatible with Apple mobile phone lossless transmission mode. The AAC encoding format is better than the MP3 sound quality, the file size is smaller, and the transmission is faster. 5. With industrial grade ceramic antenna, the RF frequency is more stable, the audio signal transmission gain reduces the antenna, the noise is 13, the noise figure of the receiving circuit such as the sound amplifier or the mixer makes the Bluetooth receiving sensitivity better. 6. Built-in 130mAh safe lithium battery, after full charge brings more than 8 hours of wireless listening, 100 hours long standby, bid farewell to frequent charging. 7. IPX5 waterproof function, suitable for running, playing, riding and other occasions. 8. Wire-controlled and battery-symmetrical design for a balanced wearing experience. 9. The ear hook is made of metal memory wire, which can be adjusted according to your own ear profile, which greatly enhances the wearing comfort. 10. Compatible with KZ ZST ZS10 ES4 ES3 ZSR and other earphones. Product parameters: 1. Weight: 11-17g. 2. Line length: 90-100cm. 3. Bluetooth version: V4.2. 4. Running time: about 8 hours, standby time: about 100 hours, charging time: about 2 hours.