The Springfield Armory Echelon 4.0C Compact Handgun brings elite, modular duty-grade engineering down into a highly concealable everyday carry layout. Built around the self-contained, serialized Central Operating Group (COG) stainless steel chassis, this innovative firearm allows the core internal system to be easily swapped across a variety of exterior frame modules. The 4-inch match-grade 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 configurations low to the slide without relying on clumsy adapter plates. Complete with aggressive slide serrations and factory-equipped tritium U-Dot night sights, this package ships with both a 15-round flush and an 18-round extended magazine for flexible operational defense.