The Wolo Bad Boy 419 and Stebel Nautilus compact are very similar. They are both dual tone horns, and are similar in looks, sounds, and price. Wolo claims 118 decibels, Stebel claims 138 - but they are from different distances. For the same price I would grab the Stebel because I've owned more of them. If one was cheaper then I'd buy the cheaper (I've owned one Wolo Bad Boy and it sounded exactly like the Stebel i replaced (a car backed into my bike while it was parked).
Important for either one - mount it using a relay and heavy enough wire. Mount it upright, facing forward, with room to intake air, and unobstructed area in front of it.
