General Pump O-ring F90391500 is a replacement for one that is broken, damaged, or worn inside KE Series, KT45M Series, and KT-WK Series pumps. It is constructed with the same material as the original for longevity and chemical compatibility. Measures 80.6 X 2.62mm. Since this is a genuine OEM part from General Pump, it is sure to fit the recommended model.