Nikon A-Series Aluminum Scope Rings, 30mm Medium, Black - 16179 A reliable optics system starts with High quality rings. Install these Nikon a-series 30mm aluminum medium scope rings to provide a steady Perch for your Nikon or other brand optics. Fit most 30mm tube rifle scopes with 30-44 mm objectives. Lightweight aluminum alloy construction; matte Black finish; fits all Weaver/Warne/Picatinny-Style bases; construction: aluminum alloy; finish: matte Black; fits: most 30mm tube rifle scopes with 30-44mm objectives; mount: fits all Weaver/Warne/Picatinny-Style bases.; order yours today! Nikon a-series 30mm aluminum medium scope rings.