6401.91 Waterproof footwear covering the knee, with outer soles and uppers of rubber or of plastics, the uppers of which are neither fixed to the sole nor assembled by stitching, riveting, nailing, screwing, plugging or similar processes (excl. incorporating a protective metal toecap, skating boots with ice or roller skates attached, shin-guards and similar protective sportswear) 25 18 15 12 9