Lyons Orff Metallophones are designed with both quality and economy in mind. These instruments begin with solid wood tone boxes, then add hand-tuned aluminum tone bars to combine for rich warm sound. All of our tone bars are backed by a lifetime tuning warranty. chromatic add-ons are separate tone boxes with the sharp/flat key to be used with a diatonic unit to have a fully chromatic set. Mallets are included with all diatonic units.