Decelerator recoil control and patented Speed-Mount insert. Pad's material and design make installation easy. Design delivers smooth snag-free mounting and maximum recoil reduction. Pad Size Fits Stocks: Small 1.5 inches to 1.63 inches wide x 4.75 inches to 4.88 inches long. Medium 1.5 inches to 1.75 inches wide x 5 inches to 5.19 inches long.