RS-E400 Pre Cured Black Natural Rubber is an economical alternative to RS-400 and is made from a natural rubber polymer. It combines the properties of good heat resistance, and very good resistance to corrosive acids and alkalies, whilst still retaining abrasion resistance. A natural polymer and abrasion resistant rubber makes it suitable for many applications. Supplied with a special CN Bonding layer which does not require buffing prior to bonding.