Kyocera DU-21 Manuel D'utilisation page 17

Warning
FCC Regulations state that any unauthorized changes or modifications
to this equipment not expressly approved by the manufacturer could
void the user's authority to operate the equipment.
Note: The equipment has been tested and found to comply with the
limits for a Class B digital device, pursuant to Part 15 of the FCC
Rules. These limits are designed to provide reasonable protection
against harmful interference when the equipment is operated in a
commercial environment.
The equipment generates, users, and can radiate radio frequency
energy and, if not installed and used in accordance with the instruction
manual, may cause harmful interference to radio communications.
Operation of the equipment in a residential area is likely to cause
harmful interference in which case the user will be required to correct
the interference at his own expense.
Radio interference requirement in European countries
The optional duplexer DU-21 is intended for use with the printer models
FS-1200/FS-1700/FS-1700+/FS-1750/FS-3700/FS-3700+/FS-3750, which
are type tested and categorized as Class B computing devices in
accordance with the EN55022 rules.
Devices in the Class B category may cause interference to radio or
television reception, par ticularly in a residential installation.
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