Stability is a key component in accuracy. In order to zero a rifle or pistol you must be able to group. Stability makes it much easier to shoot a group and get a legitimate zero. I designed this bag several years ago when I was the lead instructor and NCOIC of the sniper program for my Special Forces Group. This bag offers versatile stability for the rear or front of a rifle or a pistol. I designed the bag to have just the right amount of fill to allow flexibility to a variety of positions.The sewn in 550 loop allows the end user to attach the bag to the stock of a rifle or kit with a snap link. The bag is made from light weight and durable 500D CORDURA® Nylon and filled with polymer beads that don't absorb water(weight) The bag is 4" wide, 7 inches tall and 1" thick when completely flat. Weight is 10.5 ounces.