Marimba Yamaha YM-24004 1 3 octave Acoustalon marimba with A25 C76 range, three position resonator slots, height adjustable frame, dual angle supports and horizontal leg supports. Exclusive Yamaha tuning method ensures true pitch and full sound. Acoustalon bars, produced from fiberglass reinforced plastic in a one step manufacturing process, provide exceptional durability and a pure tone; the scientifically designed Sonic Tone Holes produced in this process give Acoustalon