Wilkins: 2 1/2″ – 6″ – Relief Valve Stem & Seat Kit for a 375 / 375A / 375AST / 475 / 475V / 475ST  Reduced Pressure Zone Assembly (Replacing the 3707-18)
 
 
Kit Includes: Upper Stem, Lower Plunger, and RV Seat

(Does Not Include Rubber Parts)