This base with pipe plugs is designed to use with Sta-Rite Posi-Flo II pool and spa cartridge filters model PTM50, PTM70, PTM100 and compatible with PTM135 Series. Also fits Sta-Rite pool and spa filters separation tank assembly and Sta-Rite Posi-Flo pool and spa cartridge filter model T-50TX, T-70TX, T-100TX, T-50TXR, T-70TXR,T-100TXR.