Convenient Locking---The rotary switch is a 4-way rotary, you can easily rotate it to 4 modes using arrows and icons to control your cat's access options: in only, out only, free in and out , fully locked. Improved Weatherproof Wiper Strip --- It provides a retaining slot with a snap for the weatherproof wiper strip to securely hold the brush strip. Even if the brush strip falls off, it can be easily put back into the retaining slot. This greatly helps the brush strip reduce noise and minimize pests such as raindrops, wind or mosquitoes. THOGHTFUL SCREWS --- It comes with 2 packs of 8 screws each, one packed with short screws and the other packed with long screws. Please screw in from both sides to prevent cracking due to attention, do not screw in only from one side. You can make 8 screws for long + long, long + short 4 screw holes, or short + short groups according to the depth of the installation door/wall. Easy to install---Instruction manual included in the sales box and step-by-step installation instructions in the installation demo video for your reference, pay attention and prepare the necessary tools for easy installation according to your needs. The tunnel depth can be reduced according to your installation needs. Suitable for --- Inner size 2.17" / 5.5CM(D) x 6.18" / 15.7CM(W) x 6.30" / 16CM(H), suitable for cats with waist less than 15.75" / 40CM. Dimensions are 2.17" / 5.5CM(D) x 7.56" / 19CM(W) x 8.46" / 21.5CM(H).