If you dont have a pferd dealer local the stihl branded files are pferd. They used to be branded pferd untill a year or so ago.
I believe Pferd makes files for Stihl.
I'm not really sure. I just know they're very good and consistent. Plus I get to go snooping around the dealer. Lol. Most other brands I've tried have been too hit and miss. It probably is true as the Pferd and Stihl 2in1 file are identical except for color.I believe Pferd makes files for Stihl.