So I really liked the idea that Layer by Layer created to make it easy to position this https://www.printables.com/model/523382-creality-k1-belt-tension-meter but I was thinking it could use one simple improvement so that you don't forget about how it should be positioned correctly.
So I used Orca to create a mirror for the right side, and also added a L and a R on the tab, to easily recognize which tool should be put left and which tool should be put right.
The author remixed this model.
I've added an indicator on the tab which indicates L or R, so that it's easier to recognize which tool should be put on what side.