Pentair 355029 Diffuser Replacement Challenger High Flow Pool and Spa Inground Pump Diffuser replacement Fits Pentair Challenger high flow pool and spa Inground pumps models CFII-NI-1/2F, CFII-NI-3/4F, CFII-NI-3/4A, CFII-NI-1A Measures 8-1/4-inch length by 2-inch height by 6-1/2-inch width