Stainless Steel Construction Guaranteed Fit & Tolerance Includes Roll Pin Made in the USA**NOTE** Due to the size of this gas tube, barrel nuts on some handguards can interfere with the gas tube and not allow you to seat the gas block properly. Below are the handguards we carry that will fit with this gas block:- Kaw Valley Precision AR-15 Konza Free Float M-LOK Handguard - AR15Discounts (this is a snug fit and will require timing of the barrel nut for appropriate clearance)- Leapers UTG PRO Arwen M-LOK Free Float Handguard - Black - AR15Discounts