Pearls Ocean Drum features micro steel balls sealed inside a double headed 16" frame drum with one Goat Skin head and one synthetic head, each producing distinctly different sounds. The natural Goat Skin head produces a more controlled sound while the clear Mylar head generates greater projection. Rolling the steel balls at different speeds, and starting and stopping produces sounds from soothing wave to crashing tides. The drums solid wood shell is finished in satin black lacquer.