This Clamping jig is specifically designed to be used with the Half-Blind Dovetail templates and Knapp Joint templates to support a workpiece vertically while cutting. It has a vertical edge reference that aligns with the Centering Scale Fence to allow for consistent workpiece registration when cutting drawer fronts and sides. This accessory is included in the Half-Blind Dovetail kit as well as the Knapp Joint Complete Template Set along with stops for those specific applications. The 3mm MDF spoil board is needed when cutting Knapp Joints, replacement spoil boards are available if needed.