New formulation - PRO is slightly lighter than original BiNaK and designed for tighter valves. It is a State of the Art oil with no evaporation factor, as it has no petroleum distillates, silicones or alcohol. It is non-carcinogenic and has no mutagens. Contains a metal protector which helps protect the interior of your instrument. Binak Pro performs well in cold weather. This oil has now replaced the Binak 495. 2oz.