Take your music on the go while still being alert to your surroundings with the Aftershokz Xtrainerz from RC Willey. The bone-conducting technology transmits sound through your cheekbones, leaving your ears completely open to hear ambient sounds. With 4GB of storage, you can store up to 1,200 songs so you have the perfect playlist for swimming, biking or so much more. Open-ear listening 4GB of MP3 storage holds up to 1,200 songs (not Bluetooth compatible) IP68 Waterproof 8-Hour battery Lightweight design for all-day comfort In The Box Xtrainerz Headphones Silicone Carrying Case USB Charging Cradle Swimming Earplugs