The Superlative Arms Solid Set Screw Direct Impingement Adjustable Gas Block is designed for AR-15, AR-10 and LR-308 platforms. It uses a bleed-off mode to vent excess gas for cleaner, cooler operation and smoother cycling. Features a solid set screw attachment, 30 fixed gas-flow positions located at the front of the block, and a DLC gas block coating. The block measures 0.875 inches in diameter and 1 inch in length. Material: 416 stainless steel. Finish: Tan.