Item Type: Bone Conduction Headphones Material: ABS + Silicone Model: K7 Bluetooth: 5.0 Support Audio Formats: MP3, WMA, WAV, FLAC Memory Capacity: 16GB Transmission Range: Approx.10m / 3ft Waterproof Rating: IPX8 Microphone Sensitivity: -37dB Speaker Impedance: 32 ohms Speaker Power: 0.6~0.8W X2 Charging Time: 2 hours (Recharge once a month when idle) Battery Capacity: 350mAh Lithium Battery (shipped with battery) Playing Time: 6-8 hours Package List 1 x Bone Conduction Headphones 1 x Charging Cable 1 x Manual 1. Bluetooth cannot be used underwater, please switch to MP3 mode before swimming.2. After charging, please install the waterproof plug on the charging port before using it to get the best waterproof ability. Bluetooth cannot be used underwater, please switch to MP3 mode before swimming. When inserting the charging cable, please make sure that there is no water in the charging hole. 1Using bone conduction technology to transmit music through your cheekbones to ensure that your ears are fully open to environmental sounds, making exercise more secure. 2Bone conduction Bluetooth headset is the highest waterproof grade IPX8, designed for longterm use in water. Designed for swimming, running, fitness, exercise and other sports. 3Builtin 16GB memory, can store about 4000 songs, avoid putting your phone in your pocket during exercise. Can be used as MP3, play songs stored, and listen to songs without a mobile phone during exercise. 4The earphone transmits sound through the cheekbones, you dont need to put the earphone in your ear to protect your hearing, you can hear the surrounding sound. 5Advanced Bluetooth 5.0 earphones connect to your mobile phone or other devices faster and more stable than Bluetooth 4.2. It is compatible with for IOS, for Android smartphone or tablet, PC computer and laptop.