This rectangular plate is part of the choke (cold-start mechanism) on the Weber DGV family of carburetors. Two of these plates close off airflow to the carburetor throats when the choke is actuated. Each carburetor requires two plates. Plates are sold individually. Fixing screws are sold separately.
Fits all genuine Weber 32/36 DGV series (including DGV 5A, DGAV, DGEV). Also fits 38 DGS series (including DGAS, DGES) and 40 DFAV only. Does not fit any other brand or model (including 32/36 DFV series).