Just a cool looking gas tube - Yankee Hill Machine Black Plated Carbine Gas Tube YHM-BL-04A

Other than being made by a quality company, there isnt too much to the gas tube. The black is a nice looking change and that is about it. Yankee Hill Machine makes some good stuff. If you dont have a handguard where there gas tube is visible, then it might be a bit of a waste. Other than that, it works for my build and looks cool in black. I have a free-float handguard with more than enough M-Lok holes to see the gas tube.