This specification covers a butyl (IIR) rubber in the form of sheet, strip, tubing, extrusions, and molded shapes.

These products have been used typically for parts such as V-rings, gaskets, grommets, and seals requiring resistance to phosphate esters or low permeability to gases, but usage is not limited to such applications. These products are not suitable for use in contact with petroleum-base fluids due to excessive swell.