IIRC that’s the same Japanese firm that was making Vernier calipers for PFM that read

out in HO scale measurements. There was a fellow in Grantham, NH who kept them in

the marketplace after PFM stopped selling them but he has been gone for some years  

now. I have two from Frankfort Arsenal and one from another firearms supplier that

were bought some fifteen years ago and all read out in either metric or English at the

push of a button. Since HO scale is metric it should be obvious which scale is used most

in this hobby, Two are in my tool box and the third is in my reloading bench. None of

these cost more than $15 and all have proved satisfactory, nor are the math convefrsions

that difficult.

Cordially, Don Valentine