About this item Satisfaction: Please refer to the back length of the correction belt in the size chart and your waist size to choose the size that fits you. Post straightener posture corrector is designed for posture correction. Every detail has been further optimized. When you use it for the first time, please control the time for about 20 minutes, then add 20 minutes a day until you wear it 2 hours a day. Stronger correction strength: Reinforced steel plate, stronger Support and better correct the bad posture of hump and chest. Closure: Velcro 100% polyester Care instructions: Machine wash Lighter and Comfortable Fabric: Bee Mesh fabric, not cumbersome and not stuffy. High-elastic fish silk ribbons: cross-strength, with good elasticity so that it will not deform when you pull it, and can be adjusted at will. Velcro is very sticky and durable. Thick cotton shoulder pads: Spread the shoulder straps to reduce resistance and avoid hurting the armpits.