1. Deflation function Compared with traditional earplugs, -APB air pressure balanced earplugs have added deflation function. 2. Without increasing distortion, it can reduce wearing fatigue and wearing deviation caused by the pressure difference between the inside and outside. 3. Effectively improve the ear canal soreness and eardrum fatigue caused by the increase in air pressure caused by the closed space between the front cavity of the earphone and the eardrum and ear canal when wearing earphones for a long time. 4. Effectively prevent the deformation of the diaphragm caused by the inability to vent air pressure during wearing, and enhance the user experience. 5. Comfortable and The is treated with silicone fine lines. Two food-grade silicone materials are used. The sound guide tube and the silicone skirt are matched with different hardness to high-quality sound transmission, long-term wearing without fatigue, and . Model:-APB Due to different batches, there may be differences in product appearance and printed text, which not affect use. Colour:B:Gray Material:Silicone Size:L Package Contents: 2 pairs * Ear-in-ear headphones Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.