Automatic Feng Shui compass.
Master Pak Hok Ming is a famous character in Hong Kong.
This luopan is designed in a floating plate system with static earth plate. Sit on top of floor plans or take a house reading by placing the compass on a flat surface, the heaven plate will rotate automatically inside the fluid to locate north.
See instructions on his website http://www.hokming.com/new_page_144.htm
AUD$80 plus postage.