content: I started using this on the recommendation of a sports car mechanic (lug nuts). I then started using it on anything that was going to be exposed the the weather. Now things like spark plugs, head bolts, license plate bolts etc. It ALWAYS works, the bolts come off w/o a breaker bar but never comes loose either. I have been using it for about 5 years now and it has never caused any kind of problem, except maybe the silver colored product itself is hard to wipe off of your hands and work clothes. Actually, that is a plus, I know it will stay where I put it, not leak out under heat or pressure. All of my friends now have a tube in their workshop, I see them using it everywhere. It is cheap enough and solves tons of problems...get a tube yourself, you will never regret it.