Flex Industrial Elbow Pads, One Size, Nylon Rubber Neoprene Foam, Black ORS NASCO silicone rubber gasket Resists aging silicone rubber gasket Resists aging 000 operations indicating a service life of 10 to 12 years of comparable use Non interchangeable oxygen and fuel gas connectors prevent accidental gas mixing Instant closure on reverse flow check valves with total shutoff at only 10 oz of back pressure Soft rubber cap is skid resistant and provides protection and flexibility Compression recovery 1 2 in neoprene foam padding provides firm consistent support without bottoming out Finished brushed tricot liner wicks away moisture and keeps out dirt and debris Secured with four brass grommets