Solid steel rings, ideal for hunting, are available for all types of optics and bases. Pos-Align Inserts offer tremendous gripping power and durability and will not damage the scope finish. Pos-Align Offset Insert Kits include one each of the following inserts:+5 and –5 (equal to +/– .005”)+10 and –10 (equal to +/– .010”)+20 and –20 (equal to +/–.020”)By combining the various sizes, you can achieve from .005” up to .040” total offset within your rings.30 mm rings come with two sets of "0" (zero) inserts and two sets of +10 and –10 (equal to +/– .010”). These are the only insert sizes available.34 mm rings come with two sets of "0" (zero) inserts, one set of +10 and –10, and one set of +20 and –20. Burris Signature Zee 34mm High Scope Rings 420590