Lathe Tool Height Gage

[Toolmaker51]

Plastic wrap and foil work perfectly and store simply, Marv. And cleaning a magnet is easy; duct or masking tape.
I use a travel indicator frequently on lathe crosslide, especially to monitor shafts and bores for bearing fits. The MightyMag has foil, the touch plate has 3 neodymium magnets mounted sub-flush, sealed flush with discs of brass .005 shim.