every weaver base is machined to the tightest tolerances for a custom in shape. They may be designed to combat the effects of draw back with a rectangular-cut notch that exactly mates to the robust move bolt in every weaver removable ring. Specs: – package deal consists of 1 base – material: aluminum – fashion: weaver – finish: matte black suits: – browning models a-bolt, a-bolt 22 stalker, medallion (the front & rear) bbr los angeles/sa (rear) – cooley seventy one (rear) – enfield (cut down like a winchester 70)(rear) – marlin mr7 (rear) – sears fifty three (rear) – winchester fashions 70 l. A.(hole spacing same), 300 magnum & 70 sa, 670 & 770(rear) observe: mounting hardware protected.