These filters fit most Dynasty Spas hot tubs as well as many others.  This is for 4 filter so you have 2 sets of 2 so that you can rotate them.

They are the same size as filter PWW50P3, PDC6000-AFS, 6CH-940.  These are microban upgraded so they have the blue filter media just like in the picture, they are not the white filter media that has no anti-microbial prodection.