You are bidding on a carburetor mfd. by Zenith Bendix, P/N 12544, in "barn find" condition. I believe this is a Model 68 and fits a number of tractors and other types of industrial / agricultural engines, possibly a "universal" aftermarket replacement. The bore is approx 1 3/16. This carburetor looks to be in good condition, the fuel inlet threads look good. Used, untested. If you know the exact application for this item please contact me so I can get it to the right guy. Items shown in pictures are what you will receive.