TriStar 97583: The TriStar Viper Series Semi-Automatic Gas Operated Shotguns are reliable, functional, and hard working. The removable choke system uses Beretta/Benell Mobil Threads, includes three choke tubes (IC, M, F), a choke box, and a wrench. Rubber Recoil pad, Fiber optic sight, and shim kits standard, backed by a five-year warranty. This model is chambered in .20 gauge and features a MO Obsession camo finish.