Flat replacement back for common dial indicators that often come with a back that has a large protruding mounting spar. The spar often prevents the use of the indicators in jigs and fixtures and can sometimes get in the way of taking of measurements at the desired location.

Looks like it should fit about half the inexpensive 2" dial indicators found on Amazon.

Printed in PETG, but PLA would likely work just as well. There are small features so a fine layer hight may help, I used 0.20mm. Otherwise shouldn't be too sensitive to settings.