Looks pretty. It is convenient to use. The errors are small.

I have used this to tension the belts on my voron printers. Before I used this I used to use a guitar tuner. This gives a good result and has good repeatability. I have managed to get the belts more balanced since using this.

Hopefully this will simplify belt testing

Item! Measured the tension of corexy belts-the touch is stretched equally but this one shows a clear difference

best one to buy! it actually fit all 3d printers. them other ones they sell with the big head don't work.