It is impossible with this "compass", made in China, to indicate where is the North that should still be the main function. She did not respond to a magnet, and turning this unit on himself supposed arrow point to the North remains virtually fixed in the case. The instructions for use, 12 pages to the size of a credit card, is incomprehensible, not because in English, but because it reported a prism that I have not found in the package and bearing a pattern clearly shows a glass prism placed on the housing. Photo by black arrows identifying the parts of the device is unreadable, because too black. Do not buy for any price!