You are bidding on a used Holley list number 1850-3 600 cfm vacuum secondary four barrel carburetor with a manual choke.  The carb is complete, and the throttle plates, adjustment screws, and other linkages move freely.   As can be seen from the pictures,  it's a little grungy on the outside, but spotless on the inside where it really counts.   As with any used Holley carburetor, all of the gaskets should be replaced before use.   These are currently going for at least $400.00 new.  Don't be fooled by the Chinese knockoffs from the Shanghai speed shop that have flooded the Ebay market as of late. Happy bidding!