Permobond® RS-3536 Tri-ply Series specially designed for chemical service, abrasionand chlorinated gas service. Built with a chlorobutyl first ply followed by a semi-hard graphite re-en-forced center for maximum permeation resistance and a flexible soft natural ply for best rubber to metal bonding. The third ply’s flexibility permits expansion and contracting with thermal variations of the metal substrate. Often used in applications such as Phosphoric Acid for it’s low permeation physi-cal properties.