Alpha Scope Ring 30mm Aluminum Sig Tactical Complete Set Black by Sig Sauer Sig Sauer's aluminum Alpha Tactical rings are machined from aircraft grade 6061-T6 aluminum and precision machined and Type 2 black anodized. Designed with the same unique industrial design as our Electro-Optics and our ring mounts not only look tough and but are tough. Features: Aluminum 2-piece cantilever design with HeliCoilsTM for locking your riflescope down with confidence