Sizing Guide Measure around the mid calf: REGULAR - 8-16"/20-40cm LARGE: 11-20"/27-50cm The Mueller Adjustable Calf/Shin Splint Suppoer is a neoprene lightweight support that helps relieve pain from shin splints, and helps increase circulation around the calf muscle. The support works by having a wraparound fit and three adjustable straps, which provide compression, and the neoprene material maintains body heat, stimulating circulation. Comfortable to wear, as the edges are fully trimmed to prevent abrasion or irritation.