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Cleaning the dust out of a pc used in a coal testing lab(r/interestingasfuck)
I wish I had such an air gun to do this with my PC.
EDIT: Alright people. Everyone uses this one: www.amazon.com/Metro-ED500-DataVac-500-Watt-Electr…, compressors are awesome but might build up moisture, and I have to secure my fans or they will fry my PC.