What are the Spacer Blocks for?

The spacer blocks are used with the Drill Guide Block to make it easier to use portably. These blocks slide on to the bottom of the Drill Guide Block. Depending on the thickness of wood you are working with, you will need to adjust the number of spacer blocks you use. Each spacer block you use will add an additional 1/4" to your setting. For example, with no spacer blocks, it is set up for 1/2" material. But when you add a spacer block, it would then be set up for 3/4" material.