To find your size do not go by your trouser size. You need to measure around your stomach where the belt will be placed. Sizes: S = 22-27" (57-69cm) - M = 27-32" (69-81cm) - L = 32-36" (81-91cm) - XL = 36-42" (91-106cm) - XXL = 42-46" (106-116cm) - 3XL = 46-50" (116-127cm). The NeoPhysio lower back support is made of premium quality Neoprene material. The back brace is a Class 1 Medical Device registered with the Medicines and Healthcare Regulatory Agency (MHRA) and is FDA approved. Provides relief from many types of back problems both nerve and muscular. Can be used for the treatment of conditions such as: degenerative disc disease, arthritis, slipped disc (herniated disc), acute back pain, lumbar spinal stenosis, muscle spasms, etc. Provides support, compression, and warmth (by trapping your own body heat) to the lower back while still being flexible enough to allow freedom of movement. Making this belt comfortable to wear for long periods of time. By keeping the back in its natural upright position, the Neoprene Double Pull Lumbar Brace reduces strain and minimises pain. Adjusting the belt to the perfect level of compression is made easy with the Double Pull elasticated straps, they provide additional stability and support where you need it most.