Springfield Armory Echelon 4.0FC with Aimpoint COA Optic 9mm Luger 4in Black Melonite Pistol - 18+1 Rounds - Engineered to merge full-size capacity with a compact slide assembly, the Echelon 4.0FC pairs a 4-inch barrel with a full-length grip. At its core is Springfield's Central Operating Group, providing a serialized foundation for modular performance. The revolutionary Variable Interface System enables direct-mount compatibility with a wide range of today's leading optics. Fully ambidextrous and equipped with tritium/luminescent U-Dot sights, the 4.0FC delivers duty-grade capacity with fast handling in a balanced, do-it-all platform. This model comes equipped with the Aimpoint COA red dot optic, installed from the factory. Aimpoint COA Red Dot Optic Installed ; 1:10in Twist ; Sights: Tritium/Luminescent Front, Tactical Rack U-Dot Rear; Slide: Billet Machined, Melonite Finish, Optics Ready; Barrel: Cold Hammer Forged Steel; Captive Recoil System; Black Polymer Frame / Full-Size Grip Module with Compact Dust Cover; Central Operating Group: The Central Operating Group is self-contained and serialized, providing a robust housing for the patent pending operating system.; Variable Interface System: By utilizing a set of movable pins, the Variable Interface System on the Echelon achieves a low, direct mount optics solution for improved sight picture and intuitive alignment.;