Wheel-type wet film thickness measuring tool.
https://www.youtube.com/watch?v=05ylwZvs_VE
Previously:
https://www.homemadetools.net/forum/...857#post163940
https://www.homemadetools.net/forum/...217#post130586
https://www.homemadetools.net/forum/...986#post160486
https://www.homemadetools.net/forum/...328#post135144
https://www.homemadetools.net/forum/...786#post156054
