Our pencil lightweight barrels are the lightest in the industry. Don't take just our word for it, major companies like Robar, Mag Tactical, and others choose Faxon pencils for their ideal balance of weight and performance. Pinned & Welded Slim Flash Hider – 16” Overall Length. Slim muzzle device measures .620” diameter. This allows a gas block and barrel nut to slide ove the muzzle device.