Unlike traditional adjustable blocks that restrict gas, the Superlative Arms system uses a patented Bleed Off Mode to expel gas forward - reducing pressure, heat and fouling in your rifle. Gas adjustment (patented) - features 30 fixed positions located at the front of the block Bleed-off port (patented) - located at the front of the block, designed to vent forward, directing emissions away from the operator 3/4 inches x 1 inches solid set screw QPQ melonite 416 stainless steel piston gas block Right hand, full-automatic AR-15 bolt carrier, dark DLC 8620 steel Carbine gas system/operating rod length