A rugged, securely mounted gas block is a critical aspect of AR-15 reliability. This lo-profile gas block will fit underneath all popular free-floating rail systems, but heavy enough to evenly dissipate heat and resist gas leakage even in high-round count use. Precisely machined from hardened chromoly steel with a dark, corrosion resistant phosphate finish this is the ideal gas block for a professional or amateur custom AR build. Precision bored to .875” and perfect for your Wilson AR barrel or the barrel of your choice. Secures to barrel with provided hardened set screws.