Area 419 Improved 1 Piece Picatinny-Style Scope Base is machined from 7075 aluminum to tolerences unmatched in the industry. The clean look is derived from the 4-axis machining and chamfered corners. The integral machined recoil lug sits against the front receiver ring to prevent any base shifting under recoil.Features:Includes both (4) 6-48 and (4) 8-40 Torx screws and wrenchMachined to Mil-STD-1913 specificationsARC Top or Full SlottedMade In United States of America