Tokyo Marui Power Down Muzzle Adapter Airsoft. A great little device that will reduce the FPS (velocity) of your airsoft gun. Now, you're thinking, why on Earth would I do something like that? Well, if your gun shoots over a field FPS limit, this is an inexpensive alternative to getting your mechbox spring reduced. The muzzle is also great for use in indoor CQB environments where you don't need a high FPS gun. Some fields require either this or a reduction in your gun to be 'field legal'. A very popular little device. Will fit on any Tokyo Marui or clone style AEG on the market.