The Tourte Round Violin mute, made of rubber, is a popular mute which is widely used. The mute stays on the instrument when not in use and then easily slipped on to the bridge when required. When engaged, the mute sits across the D and A strings, muting the bridge. The rubber of the mute is secure to use on your violin and will not damage the instrument or the strings in any way. It is also available for small size instruments.
Some players prefer the Tourte waisted or violin-shape mute giving the reason that it is more secure when not in use.