Zentech Precision 2° and 3° ski edge file guide for two popular angles, perfect for any advance skier or racer. Clamp a file or stone to the side with 2 holes, and file the ski edge to a 2 degree angle. Flip the tool over for a 3 degree edge guide. Hole pattern makes for brainless operation, even by illiterate elite althletes. Grooved face of tool rests on ski base - filings drop right through and will not get pushed into ski base. Unlike metal file guides, this tool will nor mar the ski base or case-harden edges.