This Swix World Cup Pro Stainless Steel file is a top of the line file and is preferred by most professional ski tuning techs. This new generation of files produced by Swix reduces the need for a second use of files for finishing. While this file might seem to be more expensive than others, it is because it is built to last 10 times as long as regular files which ends up saving loads of money in the long run. This particular file is 4" long (100MM) and the grit is fine (17 TPI)