This is a premium self-heating therapy support brace. There are four patent support steel plates inside,the steel plates are rust prevention, life expectancy is 3 times longer than common steel plates. It is comfortable to touch, uneasy to distort;elastic sticky buckle. Our belt gives you a warm chemical-free massage - using your own body heat to heal and relax you. Features - Color: Black. - Material: Fabric. - Size S: 100 x 15 x 0.8cm. - Size M: 105 x 15 x 0.8cm. - Size L: 110 x 15 x 0.8cm. - Size XL: 115 x 15 x 0.8cm. - Purify the blood, remove toxins;promote metabolism;improve the body immunity. - Four patent support steel plates inside,the steel plates are rust prevention, life expectancy is 3 times longer than common steel plates. - Comfortable touch, uneasy to distort;elastic sticky buckle. - High elasticity,stable sticky;high quality wool, and warm.