every weaver base is machined to the tightest tolerances for a custom match. They’re designed to fight the results of balk with a rectangular-reduce notch that exactly mates to the sturdy pass bolt in every weaver removable ring. Specs: – package deal consists of 1 base – material: aluminum – fashion: weaver – end: matte black suits: – browning models a-bolt, a-bolt 22 stalker, medallion (front & rear) bbr la/sa (rear) – cooley 71 (rear) – enfield (cut down like a winchester 70)(rear) – marlin mr7 (rear) – sears fifty three (rear) – winchester fashions 70 l. A.(hole spacing identical), three hundred magnum & 70 sa, 670 & 770(rear) notice: mounting hardware covered.