Attach this trimmer to your workpiece, press both ends against the board for a cutting range between 13mm (1/2″ and 25mm (1″), move the trimmer in the correct direction indicated by the arrow.
This will cut on both sides easily. The first cutter will cut straight, the second one can be adjusted for a tapering cut.
Both cutters are made from high-quality hardened steel and can be easily replaced when worn out.