How did you know it was a fake?

I've got counterfeit electrical goods on Amazon (solid state relay that was rated at something like 40A, but on opening it up after realizing it was counterfeit, found the electronics were only rated to something like 10A).

I complained in a review, that review never got published, despite the only SKU having only one seller - the purveyor of the counterfeit items. I did notice they blurred the logo of the real brand in some pictures later, though.