Pentair 194801 2-Inch Bulkhead Replacement Pool and Spa Filter Bulkhead replacement Fits Pentair Clean & Clear Plus pool and spa cartridge filter models CCP240, CCP3201, CCP4201, CCP5201 Also fits Pentair Nautilus and Quad pool/spa D.E. filter models NS36, NS48, NS60, NS72, QUAD 60, QUAD 80, QUAD 100 Includes 2-3/8-inch 8 buttress thread Measures 3-1/2-inch