The surface has been treated to be uneven to allow clothes to be put in and taken out without resistance. The uneven texture makes the wrinkles less visible even after repeated use. By using a patented technology backflow prevention valve, the compressed air will not return easily. Small size is perfect for storing zip shirts and fishing pants. Pack of 3 The M size is perfect for storing thin jersey suits and down jackets. Pack of 2 Please do not store clothes compressed for a long time. When compressing for a long period of time, please dry your clothes as much as possible. Sharp items may cause damage to the bag, so please close the zipper and buckle tightly and wrap it as much as possible.