The Springfield Armory Echelon COA is a full-size, striker-fired 9mm pistol built around a truly modular platform and delivered optic-ready with the Aimpoint(TM) COA red dot installed from the factory. Designed for duty, defense, and serious range use, the Echelon combines rugged reliability, modern ergonomics, and a high-capacity magazine in a streamlined, professional-grade handgun. Specifications and Features: Brand: Springfield Armory Model/Series: Echelon 4.5 w/ Aimpoint COA Caliber: 9mm Capacity: 17 |20 Action Type: Striker Fired Barrel Length: 4.5" Overall Length: 8" Twist Rate: 1:10" Weight: 24 oz Frame Material: Polymer Finish: Black Melonite Sights: Luminous Front Sight w/ Tactical Rack U-Dot Rear Optic: Aimpoint COA