This means you can choose between two completely different timbres within the Wave Drum. A sealable filling port allows you to control the amount of steel balls inside. The Wave Drum, also called Ocean Drum or Sea Drum, belongs to the family of Hand Drums or Frame Drums. The Wave Drum consists of a flat, circular frame and – unlike conventional frame drums – two heads stretched on the frame. Between the two skins of the Ocean Drum are steel balls that bead over the skins when the instrument is tilted, creating the sound of ocean surf washing up on the beach. Features Sealable filling port allows you to control the amount of steel balls inside Two different drum heads Soothing sounds Specifications Size: 16 (40,64 cm) Weight: 35,38 oz Material: Siam Oak (Hevea brasiliensis Muell.-Arg.) Material: Hand selected goat head and synthetic head Colour: WB = Walnut Brown Watch: Meinl Sonic Energy - 20 Wave Drum - WD20WB