If you want to tune your own skis but don't have a steady hand, then you need the Swix Phantom Roller Edge File Holder. This economical edge sharpener incorporates rollers for extra consistency and sharper edges.
Designed to hold the file at a precise 85°-90° angle for side-filing
Includes 80 mm file
Accepts stones up to 6 mm in width for de-burring edges