This is the white rectangular plastic float for Solex Pierburg PDSI carburetors.
Please note that there are 2 versions of floats for the PDSI and that this is the rectangular one as opposed to the black round one which can be found HERE.
Required quantity per carburettor:1
This is item number 36 in the drawing.
Please note that this carburetor was marketed as well as under the Solex brand as under the Pierburg brand.