Did you buy via Amazon's marketplace from a third-party supplier? Then I would suspect it's a *fake* Belkin cable. The complete lack of technical information is a good clue that this is the case.
Belkin's own website does tell you the spec:
https://www.belkin.com/uk/usb-c-to-usb-c-cable/P-CAB003.html
But that would only apply if you'd bought the genuine article.
Biting the hand that feeds IT
