For sale, a high-precision arc protractor for cartridge alignment.
This protractor is made of 3mm high-quality acrylic, coated with a yellow film, and high-precision laser-cut and engraved.
The first picture is for reference only; the real protractor looks like the one in the second and third pictures.
The arc protractor is the most accurate protractor for cartridge alignment; this one is designed for the following Technics turntables:
SL-1600 Mk2
SL-1610 Mk2
SL-1700 Mk2
SL-1800 Mk2
SL-3200 
SL-3210
SL-3300
SL-3310
SL-5200
SL-5300
SL-5310
SL-5350
 
The geometric features are compliant with Technics specifications; see the first picture.
 
It is supplied with detailed instructions.
We also make custom protractors to the client's specifications.