YOU ARE BIDDING ON ONE USED ZENITH CARBURETOR 20 A 1 BARREL IT HAS BEEN REBUILT AT SOME TIME AGO TOP AND BOTTOM ALL LINKAGE WORKS WELL THROTTLE AND CHOKE INCLUDING THE AIR VALVE ON THE CHOKE SPRING LOADED WHEN MOVING AROUND THE CARB YOU CAN HERE THE CHECK BALLS AND FLOAT BOUNCE AROUND FOR PARTS AND OR POSSIBLE REBUILD.I HAVE SEARCHED AND FOUND THE FIT A VARIETY OF MODELS INCLUDING PIERCE ARROW,PACKARD V12,AUBURN,CORD CHRYSLER AND LOTS OTHERS.2" AIR HORN OPENING CHOKE SIDE 1 1/2" THROTTLE AREA.TAG ON TOP STAMPED 7521 B UPPER CIRCLE AREA D 8429 AREA THROTTLE BASE SPACEING 2 11/16 THANKS FOR LOOKING HAPPY BIDDING AS IS NO RETURNS THANKS FOR LOOKING HAPPY BIDDING SHIPPING 48 STATES ONLY USA add 11.00