Springfield Armory Echelon 4.0FC 9mm Luger 4in Black Melonite Pistol - 20+1 Rounds -Engineered to merge full-size capacity with a compact slide assembly, the Echelon 4.0FC pairs a 4in 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. Features Capacity Meets Agility - The Echelon 4.0FC blends full-size control and capacity with a compact slide assembly. A full-length grip module provides recoil control, while the billet machined compact slide reduces overall weight for fast handling, resulting in a versatile pistol built for duty, defense, and everyday carry; Variable Interface System - By utilizing a set of movable pins, the Variable Interface System achieves a low, direct mount optics solution for improved sight picture and intuitive alignment; Centeral Operating Group - The Central Operating Group is self-contained and serialized, providing a robust housing for the patent-pending operating system; Full Size Grip Module with Compact Dust Cover;