The biggest feature of the SX4 Extreme Defender shotgun is versatility from running a 3-gun competition course to hunting turkey to just keeping handy when camping in the woods. Like all SX4 models, these autoloaders are powered by the ever reliable Active Valve Gas System that offers superior reliability with a wide range of loads and impressive cycling speed. Featuring a compact, 18.50" barrel; Invector-Plus interchangeable choke tube system; pistol grip stock offers an easy reach to the trigger; ghost-ring style LPA rear sight; reversible Crossbolt safety; back-bored technology; self-adjusting Active Valve System; drop-out Trigger Group and Picatinny optics rail. Includes three Invector-Plus choke tubes -F, M, IC and wrench.