Size: This is a large cat flap, external size: 23.5cm (W) * 25.2cm (H), internal size: 18cm (W) * 19cm (H), opening size: 19.6cm (W) * 21.1cm (H), suitable for installation on thin metal doors, gates and walls, cat doors are suitable for walls with a thickness of 6cm. If the wall exceeds this thickness, there will be gaps in the cat door. cats weighing less than 17 pounds (about 7.7 kg) and a waist circumference of less than 23 inches (about 58.4 cm). 4-Way Locking: The cat flap with lock has 4 switching modes. The cat flap can be adjusted by the red and green switches with labels. It can be set to open, only outside or completely locked, easy to adjust and convenient for your pet to go in and out. Cat Flip Cover: The transparent flip cover that most pets like, windshield and wiper. -Waterproof flip cover with closure. The brush bar reduces energy loss and quiet action, ensuring that pets and owners will not be disturbed. Easy to Install: Complete instructions are included, allowing