Promark FPY10 mallets feature a soft yarn-wrapped head that provides the softest articulation and maximum tone. Synthetic handles help to maximize durability. For Bass Xylophone and Bass 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)