Seriously considering one of these. I installed a large Sureflap microchip pet door last Week. Two are fine with it, but Ingrid won't use it to come in - I think the reason is that she runs at the door, which is fine going out, but going in, there is a slight delay while the lock opens, so she backs off. She got out overnight during the storm. Luckily she came when I called her, although unusually, I slept in late, so she could have been out for hours in it.