Tuning the Weber DGV carburetor means removing and reinstalling the top plate, which eventually damages the top plate gasket. A spare gasket is cheap insurance. This gasket fits 32/36 DGV (including 5A), DGAV, and DGEV carburetors. Not for DGAS/DGES or DFV/DFAV/DFEV.
This gasket is also available in the Weber 32/36 DGV Gasket Set, Part No. 1582.