Funny Jeep Wrangler JK Upgrade. Damn loud. Lower tone than electric horns. Difficult to install, had to replace the 10 amp fuse with a 20 amp one, but so far so good. There's a slight delay in the hum because it takes a split second for the compressor to kick in, but it's quicker than I expected. Mine is mounted to the frame cross member under the radiator with extension leads attached to the stock horn wires. I recommend tilting the horn down a bit so it doesn't draw water.