For GBS, Westfield, Locost, Exmo, Caterham and more. The magnets are there to simplify the location on the parts. Magnetic Jig Aligner. For Number and Letter Stamping withshank from 10 to 13mm. For Number and Letter Stamp with shank from 10 to 13mm (normally for characters between 7mm and 12mm).
eBay