Birkenstock Super-Birki 2.0 Clog The PU (polyurethane) clog Super Birki is suitable for leisure, garden, and professional wear. With its flat heel section, this popular and seamless clog provides the feet with all-around protection and grip. Fastening:Slip On Material Composition:Other Materials/Other Materials/Other MaterialsCare Instructions:The Super Birki (without footbed) can be washed at up to 80C. Flexible PU sole features a nonslip tread (certified in accordance with EN ISO 20347:2012 OB E (SRC category)). The flexible PU material with its smooth surface is water- and dirt-repellent. Ergonomically designed cork footbed. Directly foamed, flexible PU sole.