A pushy cat can push door over the lock dial
A good flap in many ways, suitable for most cats. However, the dial at the lower left only just covers/blocks the door at lower edge and a pushy cat, even if not that big (mine was 4.5kg) can ram the flap open even when locked. This was just one out of 5 cats, but once he figured this out he popped the door so often by shoving it when locked, that he cracked it.