timer switch

I have some novelty horns on my vehicle and have a question about adding switch to activate them. I would like to use a push button (momententary) that is on a timer of some sort. The hons run for about 4 seconds I would like them to turn off when the melody is complete... So Do they make something that would allow me to do this. Something that is adjustable so when I hit the button It will play for exactly 4 seconds?

Thanks again for all the help!

Directed 528t, or look at the relay section.

Thanks for the info... I'm having a hard time wrapping my head around how this is going to be wire. I've made a basic diagram of how I want to run the horn compressor to the relay up to the "normally closed" momentary switch. I'm at a loss on how to connect the 528t to all of this. I've also attached the directions that come with the unit. Thanks for the input!

Throw away the first relay, and the NC momentary switch, swap it for a normally open, i.e. the normal type that makes the circuit when you push it. One side to ground, other side to black stripe on 528t, ground the black on the 528t, 20amp fuse to red and yellow on 528t, brown on 528t to air horn compressor, don't use the orange, don't cut the loop, set the pot on the 528t for about 4secs. that's it. When you've done that I'll teach you how to turn a 528t into a variable wiper control.