These black/yellow, unisex medium safety overshoes are made of thermoplastic rubber. They are waterproof, acid/crack/chemical-resistant, and meet CSA standards. The guards measure 13 length x 5¾ width x 4¼ inches height and weigh 28 oz. They fit shoe sizes from 10 to 11 for women/8 to 9 for men and have a flatter anti-slip sole.