Simple installation steps: it can be done on wooden or PVC doors. Adapters required for brick walls, glass and patio doors Adapts to various climatic conditions: thanks to its weatherproof strip and its improved automatic double locking function, wind or the heat stay out Give your dog or cat greater freedom: it allows you to offer maximum freedom to your dog or cat; it's an ideal solution for letting cats and dogs into your home without having to open the door frequently. Your pet will be more independent Simple and practical locking: in addition to being easy to install, this door also allows you to offer maximum freedom to your dog or cat. Resistance: This pet door is sturdy and durable, thanks to its hard transparent plastic blade and high quality durable plastic frame; the door is suitable for most standard walls and doors There are four modes (1) Close the door lock in both directions. (2) means the door opens in both directions. (3) Allow cats out, but don't let cats in. (4) Entry is allowed but not exit. Easy to install, simple and generous. Good quality, using ABS material (imported ABS material) Large size, larger size, suitable for many large cats. Size model: (support selection) Size M: Frame size: height 22.3 * width 19.2 * thickness 5.5cm Door cover size: inner height 15.5cm * inner door width 15cm < /li> Size L: frame size: height 24 * width 23.5 * thickness 5.5cm Door cover size: inner height 19.5cm * width of the interior door 17 cm Shop Tips: 1. The size is manually measured, please allow the error (1-3cm). 2. Due to different monitor pixels, there may be color difference, please refer to the actual product.