Pentair WC36-22 Clamp Knob Replacement for Select Sta-Rite Pool and Spa Filters Clamp Knob replacement Fits Sta-Rite Cristal-Flo T-BP Series High-Rate Pool and Spa Sand Filter model T-150BP-1,T-170BP-1, T-200BP-1, T-240BP-1, T-300BP Also fits with Sta-Rite Posi-Flo II pool and spa cartridge filters model PTM50, PTM70, PTM100 and compatible with PTM135 series This clamp knob designed to use with Sta-Rite IntelliPro variable speed pool in ground pump Clamp knob designed to use with Sta-Rite Max-E-Pro series pool in ground pump