... ) Medium: R134a, R22, R407C, R404A/507, Water and oil 3) Material: Brass FSF series Oil Flow Switch :FSF20W- 3/4 Magnetic flow switch is ... current: 1AAvailable medium: R134a, R22, R407C, R404A/R507, oil and mixture of oil and refrigerant. Type data ModelConnection size(inch)Flow rate ... /4G3/450FSF20W-3/43/4” ODF148FSF25W-9/81” ODF194 FSF series Oil Flow Switch