Aloha SusanE,
The quick answer to your question is: other than being considered lucky to have one in your possession, the intention behind a lopan is for feng shui, and you can use them just as you would a regular compass
However they do have several rings based on calculations and representations based on the tradition the lopan comes from. You'll want to start boning -up on you chinese though.
When working with a feng shui master, there will be a point to which they will share more and more about the rings/calculations on their tradition's lopan, along with the activation, care, and other esoteric rituals of the lopan.
You'll find round and square ones, black, and red ones...heck you'll even see some with spirit levels in them (like you straight level at home for leveling pictures).
Much Love, Shawn
