the carburetor has 2 bores, 2 venturii and 2 separate but identical metering systems, one for each carburetor bore. The 2G is manually-operated choke valve. The 2GC automatic choke (integral coil spring style), 2GV vacuum choke. Need the 2G with manual choke to set up with five bros. & sisters! The 2G is mostly truck an marine an I'm havin a hard time findin em (outside of spending a fortune), thought mebe someone on here could point a finger or heard of alternatives.