Review on DRO 2 Axis Digital Readout Display With 2Pc Glass Linear Scale 5 Micron Accuracy For CNC Mill Lathe Machine (300+1000) by Eric Trask

It's a very good product with a terrible manual. The Y scale factor was trashed and not resettable after a linear cal (probably operator error). It took 6 emails to learn how to do a master clear, which isn't in the manual. So here is how: After startup, long press "8". Scroll up/down arrows until "ALL CLR". ENTER Then enter "2000" for password and ENTER.