POLAR F4 - Manual (Page 20)

The combined impact of moisture and intense
abrasion may cause a black color to come off the
transmitter’s surface, possibly staining
light-colored clothes.
If you use insect repellent on your skin, make sure
that it does not come into contact with the
transmitter.
When in non-coded mode, the wrist unit picks up
transmitter signals within 1 m / 3ft. The frame
around the heart symbol on the bottom of the
display indicates that transmission is coded.
Coding blocks interference from nearby heart rate
monitors.
E N G L I S H
20 Customer Service Information