Removes the sidewall from any ski or board type. The most important tool to use before side-edge sharpening/polishing the ski or board. Removing the sidewall allows the file to cut the edge & not be interfered by the skis or boards sidewall (due to the degree of angle on the File Guide). This tool is crucial! Square cutters are typically used for 'sandwich construction' skis/boards. This cutter also work extremely well on 'cap' type skis/boards or for those who are more skilled with their hands!