Reducer, Application Air, Gases, Potable Water, Fitting Side A Connection Type Cup, Fitting Side B Connection Type Cup, Fitting Side A Copper Tube Size 4 in, Fitting Side B Copper Tube Size 3 in, Fitting Material Wrot Copper, Fitting Side A Tube Outer Diameter 4 1/8 in, Fitting Side B Tube Outer Diameter 3 1/8 in, Maximum Operating Pressure 293 psi @ 100 Degrees F, Maximum Operating Temperature 400 Degrees F, Specific Fitting Shape Straight Reducing Coupling