Birkenstock Unisex Boston Slip-On Clogs synthetic Uppers are made of thick oiled leather that's minimally processed; they're durable, breathable, and comfortable Suede footbed liner naturally wicks away moisture EVA outsole is lightweight, flexible, shock-absorbing, and repairable This style features the original Birkenstock Footbed; a cork and jute support system that molds to each individual's footprint