These looked to be a direct replacement for freeze damaged jets in my 18 y/o Apollo Hot Tub. Not an exact replacement as those do not seem to be available. These worked, although so effort was required to adapt them. The through wall thread was slightly larger and required a small amount of grinding to open up the hole in the hot tub. Also you will need to procure new jets as your old jets are not likely to fit. Good luck!

The parts I ordered shows up when they said they would and customer service was very helpful!!