Blackpowder Products DS410B Durasight Dead On One-Piece Ring/Base System for CVA 2010-Present Break-Action Muzzleloaders and Center-Fire Rifles (High, Black) High height Integral ring/base system accommodate 50mm objective scopes and under. Fits CVA Optima Elite Center-Fire Barrels, NEW CVA SCOUT Rifle (all Models) and all 2010 Model CVA Muzzleloaders (Wolf, Optima, Accura V20 Medium (Black). All DuraSight products are manufactured in the USA using a proprietary Z2 Alloy material that is 50% stronger than the aluminum used in conventional economy mounting systems.