With a gaudy setup like that, you probably won't need to actually use the horn...that's good.
The added bulk of the grenade...er...scuba tank hanging off the bike could lead to unexpected handling issues. I would not want to be anywhere near it when the bike crashes...that's bad.

Could do with something like that on my motorbike..

I would think that mounting the tank behind the rider would give him a better pedaling position.

Stupid and of limited novelty value....
Nice, an airtank in front of the ball sack.... and a cylinder valve pointed at your face - cool - only 2000 PSI behind that as well.

Since the pain threshold is 140db, what's the point of 178db other that making more people hate bicycles? The police should cite him for reckless endangerment.

Oh please people - clearly this wasn't created for actually riding around on.

Is that a horn or a stun-gun?!
I have a small air horn already on my bikes, which works very well and loudly. It's called the Delta Airzound bike horn: www.deltacycle.com/Airzound-Bike-Horn . The manufacturer says it's 115 db. It uses an ordinary carbonated drink bottle as the air reservoir, and you fill it with 80psi of air through an ordinary bicycle valve like inflating a bike tire. It lasts for about 50 short blasts.

This is not a bicycle with a horn. This is a horn that you can ride.

+1 for Delta Airzound, it's very loud, like a car's horn. A lifesaver for commuting.

I think my brother the bike rider needs one of these ;-)