Clear-Com RS-602 (No longer available) - Manual (Page 8)

R S - 6 0 2 / 6 2 2 B E L T P A C K 4
5. Adjust the sidetone and incoming volume levels
for both channels as you and others on the
channels speak at the anticipated levels for the
application.
6. To send a call signal, press the button labeled
“call” for the appropriate channel.