This is a Sig Sauer Ring known as the Alpha, model SOA10007.
Sig's proprietary steel alloy ALPHA Hunting Rings are machined with an exactness that is both strong yet ductile that allows their rings to form around a riflescope" yet will not damage scope under proper installation. The steel rings are epoxy powder coated to prevent oxidation and resist gun oils" cleaning solutions" and outdoor exposure.
Steel weaver-style rings
Covered by Sig's infinite guarantee