By far the most accurate reproductions of popular pistols / revolvers; and the most effective in AirSoftBB gun performance which run on a gas driven mechanism. Low-temperature carbon dioxide (CO2), environment safe Freon, or Green Gas are the most popular of gases used. All models are manufactured to a very high degree of detail, weight, feel and dimension, these are for the more serious gamer / shooter / trainer or discerning collector. (The best sidearm's for serious gaming / training.)