Highest IPX8 Waterproof Level - IPX8 waterproof is designed for use in water, eliminating the possibility of water ingress. Waterproof Earphones are also great for listening to music/e-books who build up a good sweat in gym, swimming, sauna and steam room. Built-in 16GB memory - Wireless headphones have a large 16GB memory, you can delete/download songs or manage music folders via computer. Effectively avoid carrying a phone when exercising. Enjoy Sports - Bluetooth headphones' 10mm nano-composite film delivers a wide dynamic range and 6D bass effect. Noise reduction and support for HD voice calls. Significantly reduce sound leakage while swimming. MP3 Player & Bluetooth 5.0 - The latest Bluetooth 5.0 chip provides you with high Bluetooth audio quality, bringing stronger and faster connection. Reliable wireless technology makes you free from the annoyance of wired. Switch MP3 mode, let your swimming sports are not restrained. Please Note Before Ordering - Since Bluetooth cannot transmit underwater, the Bluetooth mode will not be able to connect with phones underwater. It is recommended to switch to MP3 mode before swimming. Headphones has downloaded 300 songs for users test MP3 Mode, audio format supports Mp3/WMV/WAV/Flac/APE.