The TriStar Viper series is a semi-automatic, gas operated shotgun that is reliable. Its removable choke system uses Beretta/Benelli Mobil threads. The Viper features manual E-Z load mag cut-off, vent ribbed barrel with matted sight plane and fiber optic front sight and chrome-plated chamber. Includes shot plug, three choke tubes IC, M, F, choke box and wrench.