Air Flow Switch, Ambient Temperature - Maximum 300 Degrees F, Ambient Temperature - Minimum -20 Degrees F, Connection Size 1/2 in, Connection Type FNPT, Contact Rating (DC) 20 V, Filter Rating - Maximum 50 micron, Flow Rate - Maximum 20 gpm, Flow Rate - Minimum 0.5 gpm, Flow Switch Type Piston, Hazardous Location Specification Class I, Div 2, Group A, B, C, D, Housing Material Brass, Media Temperature - Maximum 300 Degrees F, Media Temperature - Minimum -20 Degrees F, Overall Height 2 in