Low Profile Gas Block for .750″ Diameter Barrel at the Gas Port. Fits Underneath Most Free Float Handguards. Precision Machined from 4140 Steel to Exacting Tolerances. Durable and Corrosion-Resistant Phosphate Finish. Compatible with Direct Impingement Gas Systems. Includes Gas Tube Roll Pin, Serrated Self-locking Set Screws, and 3/32″ Allen Wrench for Installation. Recommended torque value of 12 in-lbs.