Looking for a quality/loud little horn

Most older bikes I pick up have poorly functioning or non-functioning horns.
What is your go to replacement horn?
I'm not looking for something big, that requires a relay, just a standard size disk horn.

I've got a KZ700. It's got a small car horn nestled under the plastics behind the seat. I got the bike that way. It's current draw is just low enough that it doesnt seem to need a relay. I got the original disk style in a box, but they were not functioning.

Comparing to a modern bike, my horn is loud to the point of absurdity. I can try to get some specs/make/model off the horn I have, if you'd like.

My original horn sounded pretty pathetic and I thought of replacing it but took it apart one day on a whim, cleaned the crud off cleaned the contacts at horn and handlebar and that made a dramatic difference.
There's not much to them. 

Fiamm makes a Low Tone disc horn that is about the same diameter as a Kawasaki unit. Center mount with 2 spade connects and produces 125 dB. You can buy them at almost any place that sell automotive parts.

I believe I took one off a bike I bought so they have been around a long time. Italian build quality is pretty good.

PMC also sell a replacement disc horn, Nikko brand made in Japan that Z1 ent sells but is not as loud as the Fiamm unit at 105-110dB.
 

I'm putting this one on the 440; it's very loud and does not require a relay. It's currently $11.55.

www.amazon.com/dp/B08HQPPTZS