A piece of expensive plastic, which served its purpose well.

The lens hood is working properly. Scattered light is much more effective avoided according to my observations, than in those where were omitted four "corners" (as for standard zoom 15-85mm). Five stars for the functionality.

But:
It lacks an orientation point, as with the lens hood for the 70-200mm, where you can quickly and accurately fix to the lens. Must go Wenns quickly, I am so sometimes rather slow because the lens hood when screwing then also like canted times.
In addition, a lock would be (as the new 100mm macro) extremely great since I've already lost a lens hood when sailing. But this sits quite tight.
Extremely annoying the price. Canon should attach the lens the lens hood prefer. You need this anyway.
So you have to buy separately to both.