Yarn, Medium Soft 1\ Yellow Marimba Finest grade synthetic, rubber, cord or yarn are used for each Musser mallet and are carefully balanced for flex, weight, size and tonal response. Rattan high quality mallets feature select rattan handles. Rubber heads are hardness-graduated for a wide selection of tonal responses. Finest grade cord or yarn is used on covered mallets. Each mallet is care-fully matched and balanced for flex, weight, and size."