We suggest you read this, if you wish to save money on replacing your jets!
The "Diffuser" is the rear white/stem/neck part on all Waterway (Cluster Storm/Mini Storm/Poly Storm/Power Storm) & Pentair (Cyclone, Cyclone Luxury & Mini - Series) jets.
In many instances all you would need to purchase is a diffuser if your jet nozzles keep falling out of their jet bodies, no need to replace the entire jet!
A precursor to the diffusers going bad is a white scummy residue on the water surface. As these parts degrade/disintegrate every 3-5 years depending on; how well you maintain your water & the quality of your areas water.
They are something you will need to purchase at least once in the lifetime of your spa!
If you have a Spa which uses Proprietary Waterway Jet faces such as Dynasty, Master Spas & others these diffusers are the same and will save you a lot of money!
CalSpa use proprietary Pentair jet faces now you can just replace the diffusers!