Product review (2 stars): Flimsy with very sharp edges
As other reviewers have noticed, the product is very flimsy, with very thin metal (like metal flashing) used for construction. As a result, the plate buckles a bit under the weight of the window, and it easily bends out of shape if you put too much pressure on it. Also, watch out for all the sharp edges -- you can easily cut your fingers. An alternative solution would be to purchase a window screen insert, and cut a hole in it for a vent which you can buy separately. Otherwise, if you are willing to accept its deficiencies, it pretty much works as advertised.