By default, the speaker on the RM-25R, RM25R-WP, RM45 & RM60 mobile radios is always on even when connected to an intercom.
Use this cable to turn off the radio speaker so your radio traffic is heard only through your communication system (headset / helmet kit).
SPECIAL NOTE WHEN USING EXTERNAL SPEAKER WITH INTERCOM SYSTEM
When using an external speaker connected to your radio, please note the following. To make sure radio traffic is also heard in your headset or helmet kit, you must use both the CJ-SPK-DC and SPLITTER-MONO-3.5. Together, these will disable the radio speaker while passing the signal to both the external speaker and into your intercom. (see diagram below)