Sena 50C Quick Start Manual page 17

Enable/Disable Mic (Default: Enable)
Users can enable/disable the microphone when communicating in a
Mesh Intercom.
Reset Mesh
If a headset in an Open Mesh or Group Mesh resets the Mesh, it will
automatically return to Open Mesh (default: channel 1).
HOLD
1s
HOLD
8s
"Mic on" or "Mic off"
"Reset Mesh"