That typically isn't air (80% Nitrogen 20% Oxygen) but a liquefied compressed gas such as 1,1,1,2-tetrafluoroethane. They're very handy for cleaning things, esp

That typically isn't air (80% Nitrogen 20% Oxygen) but a liquefied compressed gas such as 1,1,1,2-tetrafluoroethane. They're very handy for cleaning things, especially computer heat sinks. Much more portable and cheaper than an air compressor.