The Wave Drums create the soothing sounds of the surf, with 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 timbres within the Wave Drum. A larger drum with a bigger, fuller ocean sound. Best for group sessions, 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: 20" (50.8 cm) diameter, 45.5 oz (1290 g) weight Material and Color: Siam Oak (Hevea brasiliensis Muell.-Arg.), Walnut Brown Hand Selected Goat Head Synthetic Head