1. Brand new and high quality. 2. Especial creative design wireless bone conduction headphones anti pollution mask. 3. Headset uses the bone conduction speaker so the sound can pass through the skull directly to the auditory center, which eliminates many steps of acoustic transmission. It can achieve clear sound reduction in a noisy environment, so as to release the ears and revert to the delicate tone function. 4. Sports masks use one-way breathing valve. When one exhales, the silica films will bounce and discharge exhaled gas. It neither becomes stuffy, nor foggy when wearing glasses. When inhales, the silica films will fall, enabling the air to be breathed in through a cotton filter which can effectively filter out exhaust from automobiles and particulates that has the minimum diameter of 3 microns (less than PH2.5). The filter is of KN95 filter level which is especially suitable for sports like cycling and jogging. 5. Products should be stored under a cool and dry environment with 0~45C temperature. This product is not entirely waterproof so do not use underwater. Check before charging if there is any liquid to prevent headset damage. 6. Please adjust the volume when using the headset to avoid hearing damage.