This is the Medium sized version of the Saunders Posture S-Port, which can be worn against the skin or over a t-shirt or vest.It is easy to adjust using Velcro-style straps, which provide a gentle, continuous pressure that eases the shoulders, neck and spine into the proper alignment. This helps to alleviate pain and to prevent further problems from recurring. The straps are covered with soft cotton fabric, which lies flat on the skin without nipping or dragging.