Details1. The two protrusions should be attached to the skin at the same time, avoiding covering the hair and clothing. If they cannot be attached at the same time, it may not work properly. For best results, gently wet your neck with a small amount of water.2. In order to meet the needs of all users, and the initial gear is low. If you simply press the gear key two or three times, the product is still in the low gear. If you can't feel it, you can try to increase the gear multiple times.3. Sometimes you may feel discomfort during use, but this will not affect your body. Just lower the gear.