Uuni Pro comes with a Wood and Charcoal Burner as a standard. You can use any charcoal that is suitable for cooking, as well as pieces of dry hardwood (up to 25cm (10") long and 4cm (1.5") in diameter) in this burner. 

For the  Pellet Burner, we recommend Uuni Pellets, which are 100% hardwood and food-safe. The Gas Burner runs on propane.