Kalso Earth Women's Instinct Fisherman Slip-On Shoes Rubber 3.7 degree incline sole helps burn more calories and strengthen and tone muscles. Anatomic arch support helps promote a natural, aligned stride. BioFoam cushioning, made of 70% recycled content, absorbs shock for softer steps. Leather upper, polyurethane upper lining, leather sockliner, thermoplastic rubber outsole... BioFoam insole. Care: Buff with a leather cleaner or polish. Wipe off with a dry cloth.