The Kano model combines the anatomical design of the original BIRKENSTOCK insole with an additional latex heel cushion and an air-cushioned polyurethane sole. This model features an adjustable metal pin buckle, an anatomically shaped PU insole, and an oil and grease resistant PU (polyurethane) outsole. BIRKENSTOCK uses Birko-Flor®, a skin-friendly, tear-resistant, and easy-care synthetic material, as well as natural leather with a thickness of 2.8 to 3.2 millimeters for the upper material. Polyurethane (PU) is a flexible, water-repellent, and dirt-repellent synthetic material that makes shoes easy to maintain and is perfect for outdoor use.