The YMRD-2400 is a 4-1/3 Octave Acoustalon Marimba features 3-position resonator adjustment and a height-adjustable frame. The wide body design for lower bars enables superior tone and projection. The Acoustalon bars with sonic tone holes provide the most realistic sound to rosewood with unparalleled durability and consistency in all types of weather. While the gas shock height-adjustment capability is both smooth and convenient, the square-reinforced frame maintains a sleek, modern look. Durability has not been compromised as the 6" wheels make pushing the marimba over grass, turf or gravel easy.