Bone conduction headphones Works by vibrations, sound transmit via cheekbone to inner ear. Open-Ear design helps you stay alert to your surroundings, avoid danger meanwhile use it. There is almost no noise during sound transmission. Bone conduction saves many steps of sound wave transmission, can achieve clear sound reproduction in a noisy environment.2. IPX8 Waterproof Underwater for Swimming IPX8 waterproof swimming headphones,enjoy the joys of sports and music,don't worry about rain,sweat anymore.Even make it come true to enjoy music swimming underwater 10 Meters.3. Open-Ear Design Open-Ear design allows you to fully perceive the sound of surrounding envirenment while listening to music during cycling or outdoor sports, thereby avoiding potential dangers.4. Two Modes SD card & Bluetooth V5.0 Technology. This bone conduction headphones built-in 16GB Memory Card, included MP3 player. Allow you to enjoy your favorite music directly from the headphones, no need other device. The latest bluetooth 5.0 chip brings stronger and faster connection. And it is truly wireless to make yourself free from cable mess. Supporting a variety of Bluetooth-compatible devices, iOS and Android Bluetooth-ready smartphones or tablets and Mac and PC computers and laptops.Package includes 1 X Earphones1 X Magnetic quick charger cable1 X User's manual1 X Silicone Strap