Thank you for viewing. This item is unused, although it has been opened for inspection, function check, and photography. Please note that the outer box may have some damage, such as scratches and sticker residue, due to transportation and storage. 【Convenient Lock】 The knob switch is a 4-way rotary type. You can easily switch between the four modes with arrows and icons. In only, out only, in and out, can be locked freely. 【Improved Weather-Resistant Brush Strip】 Provides a snap-tab fixed groove for the weather-resistant brush strip, firmly securing the brush strip. Even if the brush strip comes off, it can be easily returned to the fixed groove. The brush strip greatly helps to reduce noise, stop raindrops, and maximize wind and pests like mosquitoes. 【Careful Screws】 It comes with two packs of 8 screws each, one with short screws and the other with long screws. Screw in from both sides to prevent tearing, not just one side. You can make 8 screws in 4 screw holes in long + long, long + short, or short + short groups depending on the depth of the door/wall being installed. 【Easy Installation】 Step-by-step installation instructions are included in the instruction manual included in the sales box and installation presentation video for reference, and can be easily installed with care and as needed. The depth of the tunnel can be reduced depending on the installation requirements. 【Applicable】Outer size: 5.5(D) x 26.92(H) x 23.62(W)cm Inner size: 5.5"(D) x 18.03(W) x 19.5(H). It fits for installation on interior doors, exterior doors, walls, windows, cupboards, and glass.