Stebel Nautilus Compact (cos that is what the photo is of) is one seriously LOUD horn. Stebel claim there is next to no lag. Not available now from Halfords, and may be in short supply judging from a quick look.
Gigglesome forum post I'm even tempted to add a hidden one to the two speeder, but so far I've not found a seller with dimensions as to be any use to me, as I would have to fit it through one of the D shaped cut outs I have. No way would I have 2013 technology visible on a 1930 trike.
