Adjustable from 1-6 PSI (pounds per square inch) it includes brass fittings for use with 1/4 inch, 5/16 inch, or 3/8 inch fuel hose. For use with carburetor fuel systems only & engines not exceeding 400 horsepower. Select desired pressure settings via selector knob located on top of regulator. 2-1/4 inch diameter chrome plated body.