Foraineam 4 Pack Rubber 4/4 Violin Practice Mute - Black Compatible with 4/4 violin, provides a high level of muting while preserving more tone quality than the metal variety. Excellent muting effect, decreasing the string volume to a minimum. Soft rubber prongs protect the violin bridge from any damage or scratches Small and compact design, easy to use, just put it on top of the bridge. Great for practicing playing violin when you don't want to disturb your family or friends.