These professional-grade instruments are carved by hand from one solid piece of mahogany. This authentic craftsmanship is needed to get the huge sound--the whole body of the drum resonates as one unit since it is hollowed from one tree. The heads are real goat skin, which is thinner than most heads so you can easily get the popping slap tones and the giant bass tones. The ropes are pre-stretched so once you set the tuning it will hold the tension (not many djembes have this professional detail). Note that diameters are listed by range due to their hand-carved nature and individual drums vary slightly in their dimensions.