Depends on what you are looking for, keep in mind some products will cause more damage if grit etc gets between the "protector" and the tank.
I've used a product a couple of times called tank slapper purchased from Aerostitch.com It's a clear 3M film, applied with water and a credit card and easily peeled off.

Oh, welcome aboard Kimmy.


It's not speeding till you get pulled over.
https://www.youtube.com/watch?v=Bqa1s4jhkQ8