There are EGO3 filters for all hot tub brands
There are two basic systems:
1 - Toploader: Your previous filter is installed in a shaft (with or without thread)
2 - Standard installation: Your filter is simply screwed on freestanding
For variant 1, the EGO3 hot tub filter model Toploader always fits, no matter how long or short your previous filter was. It doesn't matter if it has a thread, a bayonet lock, or just an opening at the bottom. It doesn't matter if the diameter is smaller. The EGO3 Toploader filter always fits.
For option 2, you only need to measure the thread diameter to determine whether it is a 2 inch or 1 3/4 inch thread diameter. And check whether you have a coarse or fine thread. These 4 combinations exist.
Measure and select the correct hot tub filter type in the shop