Improve Posture and Ease Back Pain With double Y cross design to guide your chest open and adjustable waist straps to support your waist, our back brace can prevent deformation of the spine, prevent myopia from deepening, promote your bad posture and relieve body fatigue and back pain. Metal Splints Provide Full Back Support 2 aluminum support plates inside can give you an effective support to keep your body upright . This back support will prevent the progressive spinal curvature and change the bad habits of kyphosis and postoperative repair. Universal Size Adjustable straps make it possible to fit most individuals. We have three sizesâS for Waist Circumference 26ââ to 31ââ and L for Waist Circumference 31ââto 42ââ, XXL for Waist Circumference 42ââ to 50ââ. You can choose the best back brace for you based on specific measurement.