The Superlative Arms gas piston system features a patented Bleed Off Mode that adjusts gas flow by venting excess gas forward, rather than restricting it like traditional adjustable gas blocks. 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 0.625 inches x 1 inches clamp-on QPQ melonite 416 stainless steel piston gas block Right hand, full-automatic AR-15 bolt carrier, dark DLC 8620 steel Rifle gas system/operating rod length