The Sylvan Arms weight system is perfect for adding weight and balance to your rifle. Adding weight to a rifle can cut down recoil allow for easier spotting of shots and balances a riffle. These weight mounts on any chassis or stock that is m-Lok compatible. The Sylvan Arms Q.D. attachment system allows the shooter to add or remove weight instantly without the need for tools or screws. One set of weights adds 13.5oz* to your build. Contains 1 Set of 2 weights (6.75oz* each). Quick Detach. Competition shooting compatible.