My tired 13 year old hydro-spa has several - what I call whirly gig jets, I am sure that is nowhere near the correct name.
These are about 2 and 3/8 ", have one hole on the outer edge that rotates if the pump is on.
These give a very pleasant "kneading" massage action. A little on the heavy side but that works beautifully for me.
I have eliminated several spas from consideration because they lack these type of jets, and are just a nozzle.
However, I saw a thread here on changing jets on a Caldera.
Are jets normally easy to change out by a handy consumer? I assumed it would get into gluing pvc piping, which I did not want to get into.
Any input appreciated