Description:Cover it on your instrument to prevent dust falling on the mouthpiece and protect the mouthpiece rail.Washable, no noise when dropped.Preserve reed moistore.Compatible with clarinet and alto sax saxophone.Durable, easy to carry.Size Chart:Size: Approx. 4.6x3x1.6cm/1.81×1.18×0.63inchPackage Includes:1 Piece (4 Pack)Note:Due to the difference between different monitors, the picture may not reflect the actual color of the item.Due to manual measurement, there may be 1-2mm error in size.