Burris Signature Rings are a real breakthrough in ring design. Each ring includes a set of self-centering, synthetic inserts that won't scratch the scope, yet provide perfect alignment of scope and rings and near 100% contact between the rings and scope; there is never a need to lap Burris Signature Rings.The optional offset inserts (not available for 30mm rings) allow a gun to be sighted in that cannot be zeroed with the available windage and elevation adjustments in the scope.For serious shooters, the optional offset inserts allow a scope to be brought almost to complete zero, then using the windage and elevation adjustments only for the final, fine adjustment. This keeps the erector tube centered in the scope for improved scope clarity and performance. Notes: Signature rings have synthetic pivoting inserts which increase scope to ring surface area, create consistent accuracy, give more gripping power and enable scratch free and stress free mounting. Mounting hardware included. Of...