SHOKZ OpenSwim Pro - Open-Ear Bluetooth Headphones & 32GB MP3 Player, IP68 Waterproof, Bone Conduction Headphones, Running and Swimming, Gray

Works well for swimming. I currently swim 3,000 meters, and it stays secure throughout. I place it on the outside of my swim cap and listen to audiobooks as I swim. The first time I used it, the placement felt a bit awkward and I worried it might fall off. But I've now swum three times with it totaling 9,000 meters across freestyle and breaststroke and it's never come off. I rarely need to adjust it. I don't do flip turns, though, so I'm not sure how that might affect stability. On the software side, it functions like an external drive. Convert your audio files to MP3 format if needed, then drag and drop them onto the headphones just like you would with a USB thumb drive. To activate MP3 mode, turn on the headphones, press and hold the and – buttons simultaneously. Then press the 0 button on the opposite side to start playback. You can't stream audio from your phone while swimming—no device can do that, as the physics of water prevent it. Sound quality is excellent for underwater headphones. I've used many expensive in-ear models, and this one performs better. With in-ear, you have to stop swimming to readjust if they slip. This one is easy to adjust mid-swim without interfering with your stroke or disrupting your swim watch's lap and stroke count.