This Weber gasket washer is used between the fuel inlet fitting and the carburetor body on DCOE and IDA (dual throat) series carburetors. Sold individually, one required per fitting.
This washer has a 12mm inside diameter, smaller than the similar Weber Fuel Inlet Outer Banjo Gasket Washer (Part No. WC-41530.024, sold separately) which goes between the inlet fitting and the banjo bolt head. Both washers have the same 20mm outside diameter, but the small 12mm ID of this washer will not fit around the shoulder under the head of the banjo bolt.