After having my lane space invaded one too many times, I decided to get this puppy for my motorcycle, the price seemed right and the manufacturer was well-known.
When it arrived, I was surprised that it consisted of *2* horns, not one, and that it didn't, in that case, include a relay.
So, after some amount of grief trooping around the usual parts stores (Kragen, Autozone, Napa), trying to find a relay that could be bolted to the inner fairing, installation was completed.
If success is defined by getting attention, then it worked. On the freeway, a gal driving some hopped-up something or other just decided to move into my lane, no signal, no head-turn, no lookee in mirror. One brief 'parp' on the horn, which would previously either have not been heard at all, or at most, rewarded with a snarl of derision, appeared to cause an acute panic attack, accompanied by 'mucho swervo'.
I think she never figured out that it was the *motorcycle* that was making that noise.
On balance, then, great fun. But don't think that these horns are going to make you sound like a semi truck, though.