Product review (4 stars): not as bad as some say!
It is made of flimsy metal but its made that way so you can place a thin piece of plywood in it to fit your window. The small thin plywood piece $6 @ Home Depot a envelope of stainless screws $3. I expanded the vent to fit the window, cut the plywood, then screwed the metal to the plywood. Looks professional and works perfect. Doing it this way is the only way to go to secure your window....