Originally Posted by MsMittens
I had one of those Air Horns on my Cannondale (before the bike got stolen -- *SOB*). Anyways, the button used to announce the horn eventually wore out. It was, in 1996, not a bad idea but wasn't considered for downtown annoyances and such.
THe AirZound II is much better than the older horns. This one runs on compressed air, and is filled via a schraeder valve on top, so you can fill it using your pump. It also has a volume control on it, allowing you to select anything between "mildly corrects pedestrians in a quiet environment" to "penetrates even a Lexus at a rock concert"
I personally love mine, and don't want to ride without it.