This is a limited edition colour available only via Wild Things. From Birdwell: "A modern version of the classic 301. The 310 sits lower on the waist than the 301 and we've replaced the Velcro with a simple button fly. The tab closure allows for an adjustable fit and there is a key loop and drain hole in the back pocket. Made with the same fast-drying SURFNYL material developed by the Birdwell family."