Springfield Armory Echelon 4.0C with Aimpoint COA Optic 9mm Luger 4in Black Melonite Pistol - 18+1 Rounds - Engineered for carry, the Echelon 4.0C retains the key features of the full-size model, with a shorter 4-inch barrel and compact frame for enhanced concealability. Its revolutionary Variable Interface System provides unmatched direct-mount compatibility with today's leading red dot sights, complemented by tritium U-Dot irons for fast target acquisition. The serialized Central Operating Group is housed in a compact frame. Equipped from the factory with an Aimpoint COA optic and the VIS Optic Mounting System, this pistol is optimized for rapid target acquisition and adaptability, while its 4in barrel and reduced weight make it an excellent balance of concealability and shootability. 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 / Small Grip Module; 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.;