The Birkenstock men's black regular slip-on shoes are one of the first closed-toe styles, London's simplicity shines with clean lines and an adjustable buckled strap. Made in Portugal, unique characteristics of the oiled leather are highlighted by a rich oil treatment and develop a natural patina over time contoured cork footbed that conforms to the shape of the foot and features pronounced arch support, a deep heel cup and roomy toe box, lined with suede and lightweight EVA sole for cushioning and shock absorption. Avoid extreme heat.