Seiko S833 Instructions Manual page 101

CAUTIONS
1
This product can be used only in Japan.
Since some other countries have limitation on use of radio waves,
the person who uses this product may face penalties for usage.
Note that if this product is used near devices that
emit strong magnetism or in places with a strong
magnetic field, an error may occur in measurement
of the direction, etc., or it may become impossible to
measure with this device.
In addition, a correct measurement is impossible
in environments with metal, etc., in buildings that
block the earth's magnetism. Take measurements
in environments where there are no metal shields
around.
101