Years ago I bought one of these in the 440ml size which is slightly cheaper than this.
I paid over 3 times this amount and was surprised to see this listing so could not help myself .
38-51mm Universal Yoshimura Motorrad Auspuff Schall dämpfer Rohr Flucht für BMW Yamaha Kawasaki - AliExpress 201355758
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Listing for the 440ml muffler.
This is not a direct replacement as it is designed to be held on with the supplied springs to the adapter that must be welded to the header.
On my 443 I have welded it to the header using the adapter.