Ricoh IM C300 Service Manual page 1482

Fax Option Type M41 (D0CK02)
13. Attach the serial number decal on the rear cover.
14. make a loop as shown in the illustration at a point 3 cm (1.2 inches) (A) from the end of the
modular cable on the connection side of the machine, and attach the ferrite core to the loop.
15. Connect the modular cable with the ferrite core to the "LINE" jack.
16. Attach the EMC Address Decal [A] on the rear cover (EU only).
SM 7 D0CK