Penn Arms 40MM launchers are manufactured using 4140 hardened steel, 6061-T6 mil-spec anodized aluminum and DuPont super tough glass filled nylon. These launchers are light weight, versatile and used world wide by police and corrections officers. The 40MM launcher family of products is available in single-shot, spring-advance multi, and pump-advance multi-versions. The end-user has the option of fixed or collapsible stock when purchasing any of these launchers.