Golden Calipers
thingiverse
Unable to locate a similar one; thus, I created my own, though not flawless, it's quite close. Here are the directions: Print two arms, one mid-leg, and one mid-support (unfamiliar with official names). Adjust size as required. I used plastic rivets for assembly, but any fastener will suffice.
Download Model from thingiverse
With this file you will be able to print Golden Calipers with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Golden Calipers.