The first place to start when updating your jetted bathtub is to look at the suction cover. That is the piece in the tub with all the tiny holes in it.
There is usually a PN (part number) on this piece. There are no part numbers on any of the other items in the tub. Nothing on the jet covers (escutcheons) or the air controls.
If you can figure out the brand of the suction cover then that will usually be the same brand of Jet Trim and air controls and air button.
You can begin your search on our site by shopping by the brand name of the suction cover under jet trim. Each Manufacture of suction cover makes jets but jet trim do not have any part numbers molded onto them like the suction cover.
So you if have for example and HAI 10-6806 suction cover this is a Hydro Air so you would begin looking for your jet trim under, Bath Parts / Jet / Hydro Air and match up your parts on here to the same look in your bath tub.
If you are unable to match up what you have in your bathtub to what is shown online you may email us photos of what you have and we will match them up for you.