Friendly Tips： -After each use, please clean the oil Applicator and keep it dry to ensure hygienic safety & keep the back plug can work well. -We would suggest you use scalp essence serum instead of scalp essence oil since viscosities of liquids and oils are different, and there may be a risk of clogging; -It is recommended to pour no more than 3ml of liquid at a time, approximately halfway into the liquid serum cabin to get a better experience. -Package Include: Scalp 3 Brush, User Manual, Charging Cable, Portable Bag. -All the items are 100% brand new with complete functional verification. If you have any discomfort or are dissatisfied in any way, please contact Service Team for further assistance.