Product informationExtra largedoor Specifications Note: Outer size: 28 x 24.9 x 5.5 cm (W x H x D); Inner size: 22 x 20 cm (W x H); Cut-out size: 24 x 21 cm (W x H); Fit cats up to 12.49kg (The waist less than 60cm); Material: ABS plastic Color white Style: flap Weight: 0.5kg Make sure the pet's width and height (shoulder height) are inferior to the pet umbrella door, thanks. The depth of the door/wall/window you want to install was better than the depth 5.5cm, so 8 screws can be easily screwed in from both sides.Read More Package Includes CEESC Extra LargeDoor: 1 X LargeDoor 8 X Screws 8 X Screw Caps 1 X Installation Instructions If thedoor is too thick for the door, please use scissors or a cutting machine to cut along the line in the width of the frame.Read MoreInstallation Guide1. Draw outline on the paper board Draw thedoor frame on a piece of cardboard and cut it out. Note: You should prepare these necessary tools first, pencil, ruler, electric saw, drill, screwdriver, double-sided tape.2. Draw an outline on the door Use a pencil trace around the edge of the cut paper on the door you want to attach to. Note: In general, the average installation height is about 10-15 cm from the ground.3. Drill 4 corners for holes First, drill 4 corners for deep holes with an electric drill.4. Cut out a tunnel hole Use an electric saw to cut out the tunnel hole starting from the drilled holes.Read More5. Insert thedoor into the door. After the tunnel hole is cut out, it is better to wrap it with a layer of wood skin. And if your hole is a little big; cuts, it is quite necessary.6. Reduce tunnel depth if necessary. If thedoor is too thick for your door, use scissors or a clipper to cut off part of the tunnel along line A or B. The cutting scale is about 2-4 cm.7. Mount on the door Attach thedoor to the door with double-sided tape. 8 screws were provided. Tighten them on both sides with a screwdriver. Note: 8 screws for 4 holes on both sides, please screw in every 2 sides as shown above. These 8 screws work together, they are not short.8. Done Place the screw caps over the screw holes and press them on. Installation is complete.Read more