POS-ALIGN Pivoting Synthetic Inserts End Scope Misalignment
A highly versatile ring design that features a double dovetail front ring, while the rear ring fits a windage-adjustable rear base. Gives you a wilder range of windage setting without exceeding your scope's built-in adjustment, and preserves most of the Double Dovetail system's exceptional recoil resistance. Best if used with Burris Trumount Universal
Big Book Catalog, Issue:73, Page:266
Sinclair, Issue:5B, Page:205
Measurements are from the bottom of the scope tube to the bottom of the ring: 1"Med .270", High .390" 30mm Med .180", High .300", Extra High .420"