The dimensions of the interior part are 19.5cm wide by 25cm high and 3.8cm deep.
The exterior part measures 19.5cm wide by 25cm high and 4.3cm deep.
The porch is 19.5cm wide by 14.2cm long and 3.7cm deep. To give you an idea of how far it will stick out it is about the same length as the long side of a CD case.
The size of the hole you need to make for fitting is 18.3cm wide by 19.4cm high for a door or wall fitting. For glass fitting the size should be 18.3cm wide and 21.5cm high.
You must leave at least 2.5cm below the cat flap so you can connect the low voltage power adaptor.
The minimum thickness for your door or window is 2cm.
If you are ordering the wall version please note that the maximum width of your wall can be approx 38cm or 15 inches.
The wall tunnel pieces available from
Microchip Cat Flaps are each 4cm deep. They make a very neat finish to your installation however you can just as easily use plywood to board out the wall cavity.