The iSleepFit Posture Belt is one-size-fits-most. Wear the 52-inch belt anywhere on your mid-section between your chest and hips. Smaller users can trim the belt to fit; heating the end will prevent fraying. Secure the buckle on a non-sleeping side for comfort. Next, loosen each ball by slightly turning the top half in the opposite direction of the bottom half. Then, simply slide the balls to your non-sleeping sides and tighten. Your iSleepFit Posture Belt is ready to train you to sleep in your ideal position. To remove, simply unbuckle.