This is an approved AR-15 barrel assembly grease. You usually get half an ounce for an outrageous amount from someone making a total kill sorting those tubes. I don't want to support this business model, even if it means buying more shares than a lifetime for my purposes. Is she working? Yes. Very good. This is the correct product to assemble an AR-15 barrel with the top of the receiver including the barrel nut and gas block.