After many years of Sureflap use, I found a neighbor (non chipped)cat coming out of the cat door. It had apparently followed my cat into the door before it locked or my cat was close enough to the door that it unlocked allowing the neighbor cat access through the door. So this doesn't completely prevent a non micro chipped animal to enter.
05/03/16
: 2/5
Cool device but awful for heating bills
The catflap works well but when is closed there is a gap at the edges where cold air comes in constantly. Unless u living in a worm country I wouldn't recommend it.