Hood does not connect to the lens firmly. Locking button has essentially no function.
This is a terrible knock-off of the real thing which is available at B&H or Adorama for about $55. Which is way overpriced for a piece of plastic.
Although it is printed as a Canon product, rest assured that this is a sub-par knock-off, and it doesn't fit the lens properly. For it to "click" in lock position, it's so tight, that you risk breaking the lens.