Not every book is a good guide Thien Y, direction Devils Marble bad. Good or bad depends viewers want to watch for any position: manic receiving exhaust gases or polluted places.
Where to start, receiving the supply of gas need to set good: Celestial, Concentrate, Beatitudes, Restoration position.
For example, the main door to the house, the kitchen door, bedroom, office.
Discharging polluted places need to put in place: the Five Devils, suicide, Clerk Sat, Hoa Hai ...
For example, bathroom, barn, kitchen, chimney.

Note: Please leave the remote device from the impact on supplies from fields such as:
+ Electrical appliances: refrigerators, televisions, microwaves, electric drive, fan ....
+ The magnetic objects or save from the large sizes such as steel, magnets, magnet ...
+ Do not use the compass while standing beside the thick reinforced concrete blocks.

Distance recommendation: from 3 meters or so to ensure accuracy.

Feng shui compass applications Vietnam provided
+ 12 types of compasses include: compass direction, compass La Beijing, Bao Chau compass, compass Kim Lau and other 8 kinds of compass for each age.
+ Offer to look towards building fits with the age of the owner.
+ Provides building features five selected based on gender, homeowners see Kim Lau, see Wild Snails, Thai and Tam Tai Bach.
+ Give users a deeper approach to the issues of feng shui, how to sort, view towards the room ...
+ Use the compass always give accurate results, even when tilted.

Feng shui compass Vietnam including 2 free version and a fee. The main difference between the two versions:
+ Free: ads, no commitment to support the new version update.
+ Fee-: no ads, supports the new version updated constantly, additional new features.