The Tourte Round cello mute, made of rubber, is a popular mute widely regarded as the reference standard cello mute.
The mute stays on the instrument when not in use and then easily slipped back on to the bridge when required. When engaged, the mute sits across the G and D strings, muting the bridge.
The rubber of the mute is safe to use on your cello and will not damage the instrument or the strings in any way.
Some players prefer the Tourte waisted or ‘violin-shaped’ mute giving the reason that it is more secure when not in use.
The Tourte round mute is also available for two sizes of violin, viola, and for double bass.