Outer material: 100 percent cowskin. Inner material: 50 percent polyester 50 percent polyuraehane, 95 percent polyester 5 percent polyuraehane. Closure type: laces. Heel: flat. These BOSS Colby Derby Shoes are crafted from premium leather, offering a sophisticated look and feel. Designed for adults, they feature signature trims and a flat heel for comfortable wear. The lace-up closure ensures a secure fit.