TriStar 24188 Viper Max 12 Gauge 30" 5+1 3.5" Overall Realtree Max-5 Right Hand (Full Size) Includes 4 MobilChoke. The Viper Max is a gas operated, semi-automatic shotgun that allows you to shoot light target loads to heavy waterfowl loads utilizing a two piston system. The secondary piston can be stored in forearm for easy retrieval. It comes with 4 Beretta/Benelli Mobil Chokes (SK, IC, M, F) as well as over molded rubber grips on the stock and forearm for added comfort.