The Sikes Sack is designed to be attached to the buttstock of the rifle (using qd swivel, included) and provides excellent stability in irregularly shaped surfaces. The bag comes partially filled with light weight fill allowing it to be manipulated to less an inch thick to over 9” of height. Constructed of waxed canvas the Sikes Sack measures 3” thick x 7.5”wide x 9.5” long. Proudly made in the USA.