Take open-ear listening to new depths. OpenSwim (formerly Xtrainerz) is engineered with Shokz&&';;s signature open-ear design and 7th generation bone conduction technology to ensure bud-free, comfortable listening all day, in or out of the water. OpenSwim is completely waterproof and submersible, and features four gigabytes of MP3 storage, enabling athletes to train harder; no wires, no devices, no limits. 4GB of MP3 Storage Not Bluetooth Compatible IP68 Waterproof 8-Hour Battery Life Comfortable Under Swim Cap Designed For Swimmers Engineered to withstand all elements. OpenSwim is fully waterproof and submersible so you can swim, run, cycle, or train harder than ever before. Open-Ear Comfort Our open-ear design powered by bone conduction technology ensures bud-free, comfortable listening all day, in or out of the water. IP68 Waterproof OpenSwim has an IP68 waterproof rating and can be submerged in water up to two meters deep for up to two hours. 4GB Of MP3 Storage Internal music storage allows for a library of up to 1,200 songs ready to play at the touch of a button. Supports MP3, WAV, WMA, AAC, and FLAC for device-free listening. Not Bluetooth compatible. 8 Hours Of Music With 8 hours of battery life and easy commands such as play, skip, pause, and back-a-track, you can enjoy your music lap by lap. What&';s In The Box OpenSwim MP3 Headphones USB Charging Cradle Swimming Earplugs Silicone Rubber Carrying Case