Absolutely fabulous! I ordered the catflap at lunchtime and it arrived the very next day- excellent delivery time. My cat was being bullied by an un-spayed male cat who kept coming into our home and marking his territory. Aside from this creating an awful smell in the house, it was distressing our smaller cat no end. The microchip catflap now means our cat is the only one allowed in the house and it has done wonders for him- he's visibly more relaxed. The longer tunnel did prove a bit difficult for him to understand at first and there was a bit of hesitation in using the flap, but playing hard ball and making it so he just had to learn meant that within a few days he picked it up and was using it just like a regular flap. The only downside, however, is that our door is very thin wood (I'm talking thin ply-board, cheap rented accomodation) which meant the flap didn't sit flush against the wood when attached. A rather awkward job with a saw meant we could trim one part of the flap without damaging the scanner part (which you do NOT trim) and eventually we got it to fit. This wasn't so much of an issue for us as we could problem solve for what to do, but for those with less confidence with DIY it might be a no-no if your door is thin like ours