The rubber pad (O-ring) ensures water proof protection of the battery compartment.
IMPORTANT
Make sure to close the battery cover very tightly as shown below to prevent sweat and moisture from spoiling
the battery composition.
Correct position of battery cover
NOTICE
Use water, saliva ECG gel or other conductive liquids to moisten the conductive rubber skin contact, but do not
use Vaseline or oils which may insulate the Transmitter making it unable to detect the heart rate signals.
Conductive rubber
Apply water/conductive gel here
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