Bluetooth + MP3 Modes + Shokz App - Stream Bluetooth music and podcasts, or listen phone-free with internal MP3 storage for up to 8,000 songs. Toggle between modes and tailor your audio experience with the Shokz App. IP68 Waterproof Rating - With a triple-sealed design, OpenSwim Pro is fully sweatproof and can be submerged in water up to two meters deep for two hours, for built-in MP3 audio play while swimming. Open-Ear Comfort and Connection - Our headphones are designed for enhanced safety and extended listening. Remain engaged with your surroundings while enjoying premium audio, in or out of the water. 9 Hours of Music & Calls - OpenSwim Pro technology delivers up to nine hours of continuous battery life, plus a 10-minute quick charge to immediately prepare for up to 3 hours of listening time. Secure and Stable Fit - Engineered for a slim, lightweight, ergonomic fit that stays comfortably in place through any workout and integrates seamleassly with swim caps and goggles or sunglasses and bike helmets.