This holder for the TronXY X5S allows for mounting a thin steel ruler that runs along the Z-axis plates. Makes it easier to check if the two Z-drives are at the same height. Print twice and buy two cheap 500 mm steel rulers with a hole at one end.
Extra material for mounting:
4x M4 10mm screws (I prefer the ones with cylindrical head and hex key),
2x self-locking nuts M4 (insert into hexagonal hole)
Don't print at too low Z-resolution. I've had severe bridging issues with the upper of the triangular reinforcements.