Are you talking the level itself, or the device (blocking) used for leveling?
I never seem to trust those stick-on levels. I prefer to put a 2' level on the bumper---I checked, when the bumper is level, so is the trailer. I then move it to the tongue for front to back leveling.
I can place
THESE on the low side of the rear bumber until my bubble becomes level...thereby stopping the guess work of how many I need under the tire.
However, the other day I ran across
THIS (I am always the last to learn of things)and have added to my wish list for this year.