Weaver-style rings with individual, right- and left-hand locking clamps provide external windage changes to conserve your scope’s internal windage adjustment. Heat-treated, nickel steel gives strength and durability. Internal surfaces are splined to help grip the scope body and prevent movement or loss of zero caused by recoil. Fit all Weaver-style bases. Extension (ext.) rings add .500" forward or rearward for easier mounting of long target or mini-scopes.