Leupold 1in RM CZ 550 Rings - Medium - Use as a high-quality alternative to ringmounts sold by firearms manufacturers and as a no-tap mounting method. Because these rings are machined from solid steel, they offer superior integrity and tighter tolerances. Forged and machined steel construction Versatile, and available for many different rifles Use as a high-quality alternative to ringmounts sold by firearms manufacturers and as a no-tap mounting method for most .22 rimfire rifles with an 11mm, 13mm, or 3/8" dovetail rail. Superior integrity and tighter tolerances because we machine them from solid stock.