The number 16-5230WHT identifies the Balboa Water Group (formerly Hydro Air/ITT) Microssage Grill and Flowpath Assembly (jet internal). This is a white, snap-in, roto-style internal jet with a 3-9/16" face diameter.
As a popular, generic component from a major supplier, it has been used by many different spa manufacturers in their hot tubs.
Here is a list of some spa manufacturers that have used this specific jet internally or the compatible jet bodies:
Balboa Water Group (The manufacturer/supplier of the part)
Caldera Spas (used as a replacement/equivalent for some of their "Ultra-ssage" jets)
Dimension One Spas (used in models from approximately 1989-1993)
Great Lakes Spas (used in models from approximately 1990-1994)
Hydro Air (Original manufacturer of the part before acquisition by Balboa)
This part is often purchased as a replacement "repair kit" for older jets that are no longer rotating properly.