The Wave Drums create the soothing sounds of the ocean. They have a great new feature: we sealed the little steel balls between two drum heads, one synthetic and the other natural goatskin. This means you can choose between two completely different tones within the Wave Drum simply by flipping it over. Our largest drum with the fullest and loudest ocean sound. Best for group sound baths, larger spaces or playing outside. Special Features: Adjustable sound: the sealable filling port lets you remove or add steel balls. Fewer balls give a softer sound, more give a louder one Two different drum heads offer distinctive sounds Soothing ocean sound promotes relaxation Drumming on any side increases energy Size: 22" (55.9 cm) diameter, 3.1 lbs (1420 g) weight Material and Color: Siam Oak Hevea Brasiliensis (walnut brown) Hand Selected Natural Goat Head (variations in color and pattern) Synthetic Head (transparent)