Zeromic STHD-F1, Instruction Manual, Page: 34 / 40

For your more comfortable use
●
To protect your ears, please do not turn the volume
up too high.
●
If there are howling phenomena in receiving call,
adjust the volume.
Please stop using it temporarily if howling
phenomenon doesn’t disappear after volume
adjustment.
●
Please stop using this product immediately and
consult with the doctor when your skin feels
uncomfortable.
●
Remove the ear plug and wash away the dirt with
water when the ear plug becomes dirty.
●
We recommend to clean or replace the ear plug
for sanitary purpose when you share this product
with others.
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