In the past we offered what we thought were thick “mule” skins for congas, but a DNA test from a major agricultural university revealed that they had absolutely no horse, mule or donkey (equine) genetics. They did have bovine DNA markers, and were likely Nili Ravi water buffalo marketed as mule.
We call this skin Fat Cat™ Buffalo. It is Middle Eastern Nili Ravi, and produces dry/woody tones and has low action at thickness above 2.5mm. The playing surface is slightly dimpled and dense- ideal for folkloric styles. It is available as a Flat Skin or PreMounted™ Drum Head.
For bongo machos, we have changed to using horse skin. Horse is a bit brighter than mule skin, yet it is every bit as tough and tonal.