TIMBERLAND PRO. A1HYS288. GRIT-N-GRIND FLEX DENIM WORK PANT. DARK DENIM. Built for guys who work hard and love a good pair of jeans - Our Grit-n-Grind work pants are made from rugged cotton denim riveted in metal and designed with plenty of pockets to keep you organized during long days. Five pockets plus added utility pocket.