SCHON SCHABLONE type 2 CARTRIDGE PROTRACTOR

This unique tone arm alignment gauge allows you to check the tone arm geometry of your record player and to install and properly align the cartridge to keep distortion to a minimum.
Excellent quality and easy to understand thanks to the detailed instructions.
Made of dimensionally stable plastic and offers various measurement and adjustment options for overhang, cranking, azimuth as well as center distance and effective tonearm length.

https://www.turntableneedles.com/assets/images/supertractor2-english.pdf