The Siberia 650 features volume and mute function controls directly in the left and right ear cup of the headset.
The inner left ear cup ring features the mute function. Rotating the ear cup ring forward will mute the microphone. Rotating the ear cup ring back will unmute the microphone.
The inner right ear cup ring features the volume control. Rotating the ear cup ring forward will raise the volume of the headset. Rotating the right inner ring back will lower the headset volume.