The 990 AfterShock Small Size, Big Tactical Performance. Ultra-compact and easy to maneuver, it delivers 5+1 semi-auto convenience paired with a host of functional tactical features. Inside, the 990's durable gas system and a host of corrosion-resistant internal parts/finishing (nickel boron-coated gas piston, magazine tube, hammer and sear), plus an enlarged/beveled loading port, elongated elevator, and anodized follower combine for smooth operation Outside, there's the ergonomically-designed AtterShock grip with rubberized palm pad, a streamlined forend with Mossberg signature texturing, and an embossed strap fora solid hold; plus a magazine tube extension with M-LOK mounting slots on the sides and bottom for easy accessory flexibility.