Size Guide: Please refer to the image to measure the lengths of the three sides of windows A, B, and C. Add them together: A + B + C = 3.5~4 meters. Choose 4m. [Good Air Seal and Wide Range of Uses] Suitable for portable air conditioners, clothes dryers, exhaust dryers, and dehumidifiers. Window sealing strip sizes are 3m and 4m, suitable for casement windows. Note: It cannot be installed on sliding doors and windows. [Easy to Install] No drilling or other tools required. Simply stick the adhesive strip to the inside of the window frame and the window itself. Stick the window seal onto the hook strip. Does not affect the opening and closing of windows. [High-quality material] 90T polyester, waterproof and environmentally friendly PU-coated fabric. Self-locking zipper, excellent grip, no marks when removed. It can also effectively isolate insects, dust, etc. from the room. [Convenience and economy] You can open or close the window at any time without removing the window seal. Once the