NBR (Nitrile Butadiene Rubber) stands for acrylonitrile-butadiene rubber.

NBR foam is highly flexible, resistant to deformation under permanent compression, and has high tensile strength.
It is resistant to grease, oils, and some hydraulic fluids.
Foamed NBR is primarily used as spacers and gaskets. Its application areas include the mechanical engineering, automotive, chemical, and petrochemical industries.

NBR is not resistant to aromatic hydrocarbons and brake fluids containing glycols.

It can be found in copolymers with other raw materials.
For example, a PVC/NBR blend exhibits high ozone resistance (which cannot be said for pure NBR) and has impact/shock energy absorption properties.