The Springfield Armory Echelon 4.5F Low Capacity Handgun brings premium, modular duty-grade engineering to defensive shooters living in capacity-restricted markets. Built around the self-contained, serialized Central Operating Group (COG) stainless steel chassis, this innovative firearm allows the core internal action to change exterior frame sizes in seconds. The premium 4.5-inch hammer-forged steel barrel and recontoured slide feature a rugged Melonite finish to minimize long-term cosmetic wear and corrosion. Its revolutionary Variable Interface System (VIS) allows shooters to direct-mount over 30 popular red dot optics footprints low to the slide without relying on clumsy adapter plates. Equipped with high-visibility tritium U-Dot night sights and fully ambidextrous controls, this full-size tactical package ships with two flush-fitting 10-round steel magazines.