Promark FPY30 mallets feature a hard yarn-wrapped head that provides the greater articulation. Synthetic handles help to maximize durability. For Soprano Xylophone and Soprano Metallophone The Discovery Series is designed for use on Orff and other instruments in the elementary music classroom. The mallets are extremely durable and easy to identify by beginner musicians. Head color corresponds with articulation (yellow = soft, blue = medium, red = hard)