RK212-375RVCI (Wilkins) | 2-1/2 - 6 Inch | 375/475 RP Total Relief Valve Repair KitThis is 2 1 2 to 6 Inch Zurn Wilkins 375 475 Series Reduced Pressure Zone Backflow Preventer Total Relief Valve Repair Kit. Kit Includes Relief Valve Upper Stem, Lower Plunger, RV Seat, Assembly Bolt & Retaining Washer, RV Diphragm, Relief Valve Seat Disc, Upper Plunger O Ring, Seat O Ring, And Piston O Ring, And RV Spring. Wilkins RK212 375RVCI