Feature:1. Bone Conduction Design: The sound transmits through the bone to the auditory nerve, no need to put into the ear canal, no eardrum damage, good for the user to avoid ear disease and hearing losing.2. Ear-free Keeping Danger Away: Release your ears to listen to the world, you can respond to the surrounding situation quickly, far away from danger, suitable for outdoor activities.3. BT 5.3 Connection: BT 5.3 technology enables stable connection, fast transmission speed and low power consumption. Free to enjoy hands-free calls or BT music via BT connection.4. Born for Sports: IP56 waterproof, no need to worry about sweat and splashing water. Ergonomic and 28g lightweight design ensures wearing comfort and stability, suitable for hiking, running, Cycle, climbing, driving, etc.5. Long Battery Life: 135mAh rechargeable lithium battery provides about 7 hours of playback time on one full charge. And can be recharged via the included charging cable.Specification:Overview:The bone conduction headphone releases your ears, providing you a healthy and safe way to listen to music. Using innovative bone conduction technology, the headphone conducts the sound through the bone. It transmits sound to the bone near the external canal, then to the auditory nerve. Effectively avoids the occurrence of ear damage and hearing loss, giving your healthy listening.Features:Bone Conduction Design:The sound transmits through the bone to the auditory nerve, no need to put into the ear canal, no eardrum damage, good for the user to avoid ear disease and hearing losing.Ear-free Keeping Danger Away:Release your ears to listen to the world, you can respond to the surrounding situation quickly, far away from danger, suitable for outdoor activities.BT 5.3 Connection:BT 5.3 technology enables stable connection, fast transmission speed and low power consumption. Free to enjoy hands-free calls or BT music via BT connection.Born for Sports:IPX6 waterproof, no need to worry about sweat and splashing water. Ergonomic and 28g lightweight design ensures wearing comfort and stability, suitable for hiking, running, Cycle, climbing, driving, etc.Long Battery Life:135mAh rechargeable lithium battery provides about 7 hours of playback time on one full charge. And can be recharged via the included charging cable.Specifications:Brand Name: LenovoModel Number: X3 ProBT Version: 5.3BT Profile: A2DP, HFP, HSP, AVRCPOperation range: 10 meters (no obstacle)Drive Unit Diameter: 16mmFrequency Range: 20-20000HzSensitivity: 86dB3dBImpedance: 8ohmBattery Capacity: 135mAhMusic Playing Time: about 7 hours (depends on music volume)Charging Time: about 2 hoursColor: Black, White (Optional)Item Weight: 28g/0.98ozPackage Size: 13.4*10.4*5.1cm/5.27*4.09*2.00inPackage Weight: 122g/4.30ozPackage List: 1 * Bone Conduction Headphone1 * USB Charging Cable1 * User Manual (English/Chinese)Package List:1 * Bone Conduction Headphone1 * USB Charging Cable1 * User Manual (English/Chinese) Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-YJL official store