Product review (5 stars): Made a huge difference!
My old leaky dryer vent made the floor in front of the dryer feel like a slab of ice, but this vent completely fixed the problem.  If you have an icy laundry room in the winter (due to air intrusion) this vent is a no-brainer upgrade.  (They carry them at some home/hardware stores, so you might be able to find one locally.)

Installation was pretty easy.  I pulled off the existing vent (literally pulled it off; just grabbed and yanked) and secured the new vent with a generous amount of silicone caulk.

The square wall mounting plate on this product is significantly bigger than my old vent, so it took a little wrestling to get it in place behind the vinyl siding, but in the end nothing needed to be taken off or altered, so it was a fast, easy job.