Tested and certified according to the standards UL 181 / ULC S110 Class 1 air connector.

TYPE RPL -  3 ply aluminum foil, totalling 45 microns thick (.009mm) and resists up to 20” of static pressure. The inner, middle and outer plys incapsulate a spring steel helix and contain no openly dangerous constituents such as mylar (plastic) or neoprene.