Darlly 40508U FC 0172 4CH 949 PWW50L Pool Spa Filter Cartridge covervalet 0 HP Ultima and Ultima 0 HP Ultima and Ultima Plus Wet End is designed for compatible 48 frame 2 inch by 2 inch applications where the original assembly has become worn or unreliable The threaded 1 1 2 inch MPT connection makes this a practical option for supported installations that need a more direct replacement rather than a workaround fitting solution or unreliable The spa and pool application gives this cartridge practical value because multi use filter formats still require a precise reference match to perform correctly in the intended housing