Silentblock compatibility

In the item 11204000 is indicated the dimension 39x21x10mm and compatibility with Vespa 50 Special V5B1T.
I've disassembled the silentblock from the motor of my V5B1T, and the dimension is:
-internal diameter 20mm
-external diameter 39mm
-thinkness 25mm

Then, this article is not correct?

The alternative is the item 11220400, but is different!