Used on a cat 6 kg, the size is perfect as it adjusts very easily in one way or another. This harness is original on its way to attach it bothers the animal less than a conventional harness. On a dog, I think it is very easy to simply place because the harness on the ground, put his paws in the 2 holes and snap the clip on top. For a cat by cons, we must be very fast to do that because mine in loccurrence, fold their legs immediately, so you have to take it 2-3 times but it's still pretty simple to do.