WiWU O300 Openbuds OWS Bone Conductive Earphone Stereo Sound Sports Earphone Noise-Cancelling Up to 40 hours - White: 1. Comfortable to wearErgonomic design, custom embedded 0.7mm extremely thin flexible wireUltra-soft, skin-friendly, double-layer silicone is used for ear attached part2. Custom speaker, HIFI sound qualityHigh amplitude and high sensitivity driving unitThe edge’s flexible upper arc ring is made of