Buna-N is in a family of unsaturated copolymers that is typically used in fuel and oil hoses and seals. Buna-N can withstand extreme heat, and petroleum based fluids. They more Nitrile is the products composition, the more the resistance to these fluids. This however comes at the expense of its flexibility. Buna-N is also used in making V belts, disposable (non-latex) lab, cleaning and examination gloves.