Springfield Armory Echelon 4.5F Features The Echelon 4.5F 9mm full size pistol incorporates Springfield Armory's serialized Central Operating Group within a durable polymer frame for modular strength and long-term reliability. Its 4.5 inch barrel with a 1-in-10 twist rate supports consistent accuracy while the black Melonite finish enhances corrosion resistance and surface durability. The striker fired action and integrated trigger safety provide dependable operation for duty or defensive use. Factory-mounted with the Aimpoint COA optic this model stands out as a full size optics ready 9mm pistol engineered for rapid sight acquisition and improved tracking during recoil. The Variable Interface System allows direct-mount compatibility with leading red dot footprints complemented by a luminescent front sight and Tactical Rack U-Dot rear sight for reliable backup alignment. Included 17 round and 20 round magazines provide flexible capacity for range or professional applications. Springfield Armory Echelon 4.5F Specifications Manufacturer: Springfield Armory Model: Echelon 4.5F Type: Semi-Auto Pistol Action: Striker Fired Caliber: 9mm Finish: Black Melonite Frame: Polymer Grips: Black Polymer Barrel Length: 4.5 in Overall Length: 8 in Twist Rate: 1-in-10 Capacity: 20+1 Magazines Included: 2 Magazine Description: 1 17 rd 1 20 rd Sights: Front Luminescent Rear Tactical Rack U-Dot Sight Type: Fixed Optics Ready: Yes Optic: Aimpoint COA Weight: 23.9 oz Safety: Trigger Safety Additional Information: Central Operating Group