From the dock duties to running laps around the deck, the vulcanized-rubber Challenger 7" Boot sets the task-ready standard for guaranteed waterproof protection and comfort. Vulcanized rubber outer with neoprene lining Simms proprietary rugged deck outsole provides grip and traction on all surfaces Pull-on loop for easy on and off. WEIGHT: 50 oz. (1418 g) per pair size 9ITEM #: PG-13939 a Vulcanized rubber outer with neoprene lininga Simms proprietary rugged deck outsole provides grip and traction on all surfacesa Pull-on loop for easy on and off.