Hello,
The hole scaler is used for counting all those holes or ribs when you are cutting out a pattern. A plastic canvas hole/rib counter can make the job a little bit easier when doing that. Each line on the hole scaler indicates a hole or rib and can be used either for 7 Mesh or 10 Mesh simply by turning the scaler to the appropriate edge. Hope this helps?!
~Kristi @ EPC