The SX4 is built on the success of the bulletproof Active Valve System that was the core foundation of the SX3. Features pistol grip stock with spacers to adjust the length of pull and three interchangeable comb height pieces; Mossy Oak Obsession camo finish; adjustable rifle-style sights with TRUGLO fiber optic front sight; Invector-plus extra-full turkey extended choke tube; camo sling swivels; Weaver-style cantilever rail optics mount; Crossbolt safety and larger Bolt handle and Bolt release button.