For Weaver Bases
Extra wide, oval design for instant use of either iron sights or scope. Fit Weaver Top Mount Bases. Excellent for mounting large objective diameter scopes, too. Sold in pairs. Extension Standard
Big Book Catalog, Issue:66, Page:264
SPECS: Standard See-Thru or Extension style that adds approximately 3/4" (19mm) eye relief adjustment. For 1" (2.5cm) scopes. Satin Blue or Matte Blue finish.