Royal Robbins Billy Goat Nylon Canvas is named after our original Billy Goat cotton canvas which is known for its great durability and wear. This nylon canvas is quick to dry, extremely durable, and features a 50+ UPF rating. Relaxed fit. 7" inseam. Billy Goat Nylon Canvas. UPF 50+. Quick dry. Action waist. Billy Goat snap with back up button. Single front pleat. Back patch pockets.