Based on https://www.thingiverse.com/thing:1692973, a simple clip on aid to help me quickly align the bed on my FLSUN cube with the 8mm X axis rods. With the dual Z motors, I often seem to end up with one side lower than the other so I created these to quickly readjust the sides of the bed.

Print two exactly the same and clip one on each side, then adjust the sides until they both just touch. You can eyeball it or slip paper under.

I am pretty new at this, and have seen a lot of different advice on leveling the bed, but for me, this seems to work quite well to re-synch the two z-motors on the cube.