The Sure Grip is a hypoallergenic comfort liner designed to cushion and comfort. Perfect for sensitive scalps, the Wig Grip will relieve pressure points around your head, preventing pressure headaches caused by extended wear or improper fit, while securing your wig in place for a reliable fit. One important fact: This product works best when you place it on the hair, like a wig band.  if you need a wig cap, you can push the wig cap back a bit to make sure the sure grip makes contact with your hair... if you do need a wig cap.... it works better on the mesh cap.  It will definitely slip off a nylon wig cap.  The Sure Grip is easy to clean, self-healing if punctured, and non-allergenic. The Velcro® adjustment fits up to 24" circumference.  This band is mainly for comfort to relieve pressure from the wig cap.  If your wig is a little loose... it can add that extra security to keep it in place! Make sure you put the Velcro attachment area at the back of your head for best results. This is for average or large size wigs.  Unfortunately, this will be too big for petite size heads.