This is no namby-pamby little tool. We designed our Pro Piston Knocker for serious real world duty. Our tool is constructed of a non-marring composite material and measures a full 13" in length with 2" and 2 1/2" diameter ends. The 2 pound overall weight is achieved through the use of a chamber loaded with steel shot, which provides a dead blow effect; heavy striking force without rebound. We’re sure you’ll find more uses for this handy driver than just knocking pistons into their holes.