i need some canned air. i just happened to have a couple 8oz air horns. i dunno why, i just do.
carefully unscrew the back of the horn. there's a spring inside, be careful not to let it shoot out. and don't bend the metal disk. set those parts aside and you now you have canned air with a neat little handle.
the air shoots out the small hole at the bottom of the ring:
also, as with canned air, the can will get very cold during/after use. and be careful not to freeze/get the tetrafluoroethane on your skin.