Mossberg 590S models set a new standard for shotshell cycling flexibilty. Now, Mossberg has added the added benefit of optic-ready convenience. Receiver cuts allow 590S shotguns to accept low-profile direct mounting of Shield RMSc-pattern micro dot sights, for improved eyealignment and target acquisition. A coverplate is included when a sight is not mounted. Standard Pump-Action Features: Dual Extractors, Twin Action Bars, Positive Steel-to-steel Lockup, Anti-jam Elevator Top-mounted Ambidextrous Safety Convenient Cleanout Magzine Tube w/Cap 590S. The Ultimate in Shooting Flexibility: 590S shotguns cycle 1.75," 2.75," or 3" shells righ Mfg: Mossberg