The Springfield Armory® Echelon® 9mm Central Operating Group® (COG) serves as the serialized foundation of the Echelon pistol platform, providing the core component for a customized firearm build. Designed for compatibility with Echelon®-compatible grip modules and components, this standalone unit allows users to personalize their setup with compatible OEM and aftermarket slide assemblies, barrels, sights, and accessories. The Echelon® Central Operating Group® features an integrated takedown lever for installation into compatible frames and a flat-faced trigger with an integrated safety designed to promote consistent finger placement and a controlled trigger pull. Finished in black, this compact operating unit offers a foundation for building a personalized Echelon® configuration. Features & Specifications Brand: Springfield Armory® Platform: Echelon® Product: Central Operating Group® (COG) Caliber: 9mm Color: Black Serialized Component: Yes Frame Compatibility: Echelon®-compatible grip modules Magazine Compatibility: Echelon® pattern Trigger: Flat-faced trigger with integrated safety Takedown Lever: Included Weight: 3 oz. Length: 4.3 inches Height: 1.9 inches Springfield Armory Central Operating Group for Echelon Pistols EC900-RET in Black