Aluminium World Cup side edge file guide for skis and snowboards. This 4 Degree Side-Edge File Guide by Swix is the most accurate way to establish a 4 Degree edge by hand. Without the mechanics of the other file holders this guide is dead on every time. Any of the Swix files or stones can be clamped to this guide to do every step of edge work precisely. These guides are the choice for most high level technicians.