UiiSii BN28 is a dual-driver neck-mounted Bluetooth earphone. It comes with a Bluetooth version of V5.0 to enhance your music performance. The earphone got a built-in microphone and a BK3266 Bluetooth chip. It takes about 2.5 hours to fully charge it and once you fully charge the earphone, you will be able to play music/ talk for about 12 hours randomly (depending on volume), and standby time is approximately 320 hours. Uiisii BN28 Dual Driver Earphones speaker size is 6mm and the Bluetooth transmission range is 10m to offer you real TWS (True Wireless Speaker) facilities. The earphone is IPX5 water-resistant.