These are not worth the price you pay for them but I can't just be bringing my air compressor with 50' hose into the house to do the job I had to do so I was kinda forced to go this route.
Thought I was following the directions - removed the top tab as directed - but no matter what I try I CANNOT get any pressurize air to come out of the container. For me at least this can was a waste of money! (And I still don't know if my keyboard is fixable!)