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 Grace tonearms:
 
G-560L
G-565F
G-860F
G-860FB
G-660P
G-960
 
The geometric features are compliant with Grace specifications; see the first picture.
 
It is supplied with detailed instructions.
We also make custom protractors to the client's specifications.