Back brace contains 4 Memory-aluminum stays that are quadruple harder than the commonly used PP strips,and 2 steel springs placed along the waist side, offer 360 vertical support to lower back,prevent excessive rolling of your muscles and decrease the pressure on your discs . The back support made of 4-way stretch elastic material,3D knitting technology by different compression levels, for superior fit,breath and comfort. The inner layer is made of velvet fabric, giving an ultimate baby-skin-like silky touch, for dressing internally. Back support with 2 elastic straps are designed to add extra compression around lower back to prevent back injuries from weight lifting, long time standing or sitting, doing housework, working, etc. Relief waist muscles ache, disc herniation, sciatica, scoliosis etc when wearing the back belt. 2 Silicone anti-skid bands are designed on the 2 sides of the waist,prevent the waist support belt from rolling up when sitting, bending or doing other activities. The 1.5'' 3.7'' wide size Touch Fasteners of 2 elastic straps provides strong adhesion far beyond your expectations, made of PVC material that usually used for babies clothes,will not scratch your skin or damage your clothes. S: Fits waist circumference 65-80cm 25.6-31.5in M: Fits waist circumference 80-100cm 31.5-39.3in L: Fits waist circumference 90-110cm 35.4-43.3in XL: Fits waist circumference 100-120cm 39.3-47.2in 2XL: Fits waist circumference 120-140cm 47.2-55.1in 3XL: Fits waist circumference 135-155cm 53.1-61in2 Silicone anti-skid bands are designed on the 2 sides of the waist,prevent the waist support belt from rolling up when sitting, bending or doing other activities. Back support with 2 elastic straps are designed to add extra compression around lower back to prevent back injuries from weight lifting, long time standing or sitting, doing housework, working, etc. Relief waist muscles ache, disc herniation, sciatica, scoliosis etc when wearing the back belt. The inner layer is made of velvet fabric, giving an ultimate baby-skin-like silky touch, for dressing internally. The back support made of 4-way stretch elastic material,3D knitting technology by different compression levels, for superior fit,breath and comfort. Back brace contains 4 Memory-aluminum stays that are quadruple harder than the commonly used PP strips,and 2 steel springs placed along the waist side, offer 360 vertical support to lower back,prevent excessive rolling of your muscles and decrease the pressure on your discs .