This came badly wrapped in just torn polythene, which makes me think it is, at best, a grey market product. It isn't branded Canon product but at this price, you probably knew that already.
It is nonetheless a useful piece of kit, though the manufacture lacks finesse and the overall finish isn't as polished as it could be around the external outer rim. No matter, you're buying it because you know it's going to be bashed instead of your £500 lens.
Now for the bad news. It doesn't fit if you take the belt-and-braces approach with your lens. You can use this hood, or you can use a lens filter, but you can't use both at the same time. The shallow thread around the inner rim doesn't allow it.
I use a Hoya UV filter on top of my lens, partly for the shooting benefits and mostly for the protective benefits, so you may not be affected if you have another brand of filter.
But I don't know anyone with expensive speciality lenses who doesn't use filters as a matter of course. So, cheap as it is, it was money wasted for me, and the search for the right lens hood continues.