Use Weaver-Style Rings On 3/8" Dovetail Receivers
Lets you choose from a wide selection of Weaver-style rings for
nominal 3/8" dovetail. Secure, single-slot, two-piece design allows
perfect ring spacing every time and easy access to chamber. Made
of aluminum to keep weight increase to a minimum.
Big Book Catalog, Issue:65, Page:244
New Product Supplement, Issue:563, Page:009
SPECS: Aluminum, black matte finish. Each base measures
1½" (3.81cm) long.