This product is a posture , made of PU , nylon, and sponge material, and durable. It can effectively improve sitting posture, hunchback, prevent lumbar strain and spinal injury. A good helper for you to improve your sitting posture. Choose it for you. Features - Color: Black. - Material: PU , nylon, velvet, sponge. - Size S: Approx. 20cm/7.87inch (back length); 24cm/9.44inch (shoulder belt length); 38cm/14.96inch (adjustable belt length); suitable for the width of shoulder of 28-37cm/11.02-14.56inch; suitable for the weight of 40-80 catty. - Size : Approx. 20cm/7.87inch (back length); 29cm/11.41inch (shoulder belt length); 48cm/18.89inch (adjustable belt length); suitable for the width of shoulder of -46cm/12.99-18.11inch; suitable for the weight of 80-120 catty. - Size L: Approx. 20cm/7.87inch (back length); 38cm/14.96inch (shoulder belt length); 57cm/22.44inch (adjustable belt length); suitable for the width of shoulder of 40-54cm/15.74-21.25inch; suitable for the weight of 120-180 catty. - Size XL: Approx. 20cm/7.87inch (back length); 38cm/14.96inch (shoulder belt length); 67cm/26.37inch (adjustable belt length); suitable for the width of shoulder of 50-60cm/19.68-23.62inch; suitable for the weight of 180-220 catty. - Made of PU , nylon, and sponge material, durable and practical for use. - Adjustable design, both kids and adults are available. - The adhesive buckle on the side, resistant to tearing and not easy to deform. - Ergonomic design, fits the curve of the human body when worn, comfortable and does not hurt the shoulders and back. - Invisible, you can use it anytime and anywhere, suitable for indoor and outdoor use. Package list: 1 x Posture