Tecmark (TDI) 1.5PSI Plastic Pressure 3903DF

Pressure: 1.5PSI Plastic Switch: SPST 1A Field Adjustable.

This DF version of the Model 3903 pressure switch means this pressure switch is field adjustable vs. the other, fixed set point type 3903-BP that is factory adjusted and where the set point cannot be changed.

This 3903-DF is the 1 amp adjustable version that works between 1PSI and 5PSI for standard hot tub application.

1/8 inch NPT threaded connector fits the 1/8 inch pressure switch tap on spa heater manifolds or on separate tailpieces that have the 1/8 inch pressure switch tap.

This pressure switch model is same as part numbers:3903DF, 3903DG, 3903 in the 3900 series and is also a substitute for 3902. 
The adjustment slot on top comes centered but can be adjusted left or right as needed. 

Has 1/8"NPT Thread and is about 2 inches wide and 2 inches tall.

Need teflon tape? Best to wrap the threads of the pressure switch with teflon tape to assure a good seal at the pressure switch tap on the heater manifold.

3903DF is the same switch as 3903-DF and 3903.