Aluminum Alloy For Less Weight
Vertically split scope rings made from a special, heat-treated aluminum alloy dramatically cut weight without compromising strength. Tempered, Allen-head cross bolts and one clamp make it easy to remove and replace these rings.
Big Book Catalog, Issue:68, Page:275
SPECS: Aluminum black. 1" (2.5cm) or 30mm dia. Height from top of base to inside bottom of ring.