FlyingBear P905 $4 Bed Leveling

DO NOT LEAVE THE GAUGE ON YOUR PRINTER WHILE PRINTING! YOU WILL DAMAGE YOUR PRINTER.

This gauge mount makes it fast and easy for you to level your X-axis gantry with your entire printer bed, corner-to-corner to within +/- 0.01mm of accuracy or better. Your 1st layer will be the most uniform it's ever been regardless of whether you have auto-leveling or not.

It is also a great diagnosis tool for bed leveling problems. It allows you to readily see precisely how your bed leveling efforts are affecting your bed. It's much, much faster than printing a calibration grid in order to find low and high spots. In other words, you can see your adjustments "LIVE" as you make them.

There are a few different versions of these tire tread depth gauges so make sure you buy the same one. This is the one I bought for $4 and some change:

https://www.ebay.com/itm/0-25-4mm-Digital-Car-Tyre-Tread-Depth-Gauge-Tester-Meter-Measurer-Tool-Black-LJ/112664501069?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p20