The Springfield Armory Echelon 4.0C COA blends true concealed-carry comfort with heavy-duty enclosed-emitter optic precision. Purpose-built around Springfield's modular, serialized Central Operating Group (COG) stainless steel chassis, this defensive 9mm scales down to a compact frame footprint to maximize deep concealment potential without giving up full-size durability. The defining highlight of the EC9409B-COA configuration is its factory-integrated Aimpoint® A-CUT slide profile. This specialized interface direct-mounts the included Aimpoint® COA enclosed red dot sight straight into the slide metal, dropping intermediate plates completely to lower the zero height-over-bore and ensure premium zero retention. Shipping with a 15-round flush magazine and an 18-round extended backup, this weather-sealed everyday carry bundle arrives safely secured inside a premium factory padded soft case.