Templates interlock to form stable pattern during routing. Secure patterns to work surface with masking tape, self-adhesive discs, or double stick tape (sold separately). For use with plunge router that accepts standard 1-3/16" (30mm) template guides. Each letters set includes 40 letters with duplicates of common letters and three spacers. Each numbers and symbols set includes two each of 0 - 9 and 9 common symbols including @ and &. 3-3/8"