at first i thought this would be too much of a visual obstruction to be useful, but we tamp down the middle and we can see over the top and through the rear window in the mirror or over top. We have small dogs. I think a big dog might climb over the way we have it set up. The zipper feature is really nice but if we don't zip it completely, and position the zipper (a two way zip that makes a u shape in the middle of the barrier), our dog can just unzip it and come on through to the front. Still - it's effective and worked for us on a roadtrip. I like most that you can slip it on and off easily on top of the headrests, without affixing all of the clips.