This precision Tracing Compass guarantees accuracy when laying out the Flying Stars on any size floor plan. It is transparent so you can see the floor plan beneath it; it is perforated to make the plotting accurate. This Tracing Compass comes with separate perforations for the 7.5º sector located in each compass direction indicating the overlay of the Heaven and Human plates of the Lo Pan for those who know how to use the Special Water Placement Formula found in the Water Dragon Classic. Illustrated instructions are included.