So I've got an 02, accidentally bought an 04+ head, and have some extra parts that I can't identify. I know some of this is to the PAIR system, but can anyone explain to me what exactly these things do?

A horn and a camchain tensioner

a gs500 horn? mine looks way different. is it louder/less bitchy than the early model horns?

None for the PAIR system.

Red after market loud horn
Right: breather hose for carbs. Newer ones have that small round filter. Older carbs had just a hose back over the air box.
Middle: Cam chain tensioner. keep it in case you need a new one. They're all compatible over all years
Lover right: Vacuum operated switch mounted on the carb bowl of the right carb. 2004+ models only.
Lower left: A vacuum reservoir. Just an added part on the new carbs probably to smooth out the vacuum due to the vacuum operated switch which you wouldn't want to go on and off erratically because it connected to the ICU in 2004+ models for engine timing adjustments.

Now ask me a tough one.

Adidasguy beat me by seconds due to problems finding the pic... But I was gonna use his pics anyway lol...
Ill add that the horn should be quite a bit louder than stock as it is a dual tone.  Should be a pretty simple plug and play if you want to try it out.

- Bboy

Horn would be dual tone if he had two. There is only one. But it will be much louder.

Quote from: adidasguy on November 03, 2012, 10:03:26 PM
Horn would be dual tone if he had two. There is only one. But it will be much louder.

This is fantastic news.

...could I have 2???

Ah yes there is a low tone and a high tone model for those type of horns... That one looks like an older model of the fiamm or blazer horns but I couldn't tell ya low or high tone.

- Bboy

My Mazda 3 came with only one of those type of horns.  I replaced the single horn with 2 of the same kind with different tones.  I just wired them in parallel and they work good.  Now my car horn doesn't sound like a clown car.