This won't stop a determined thief but it will stop a spur of the moment try at stealing my trailer spare tire. As always it's a balance of cost, ease of use, and protection. This is very easy to use and is a decent price. My feeling is that if someone really wants to steal my spare they'll pretty much defeat anything I can protect it with unless I want to spend a lot of time and trouble removing the protection ever time I need to use the spare myself. As you can tell, I don't want to go to that much trouble. Now if I left my trailer alone in a place easy for thieves to access, it might be different. But then I think I'd have a lot more to worry about that just my spare tire!