Durable Material: Portable AC Unit Air Conditioning Window Kit is made of durable PVC, lightweight and portable, easy to install and remove, suitable for home or office use. Good Sealing: Insert the board into the window rail and tighten to achieve a secure seal, helping to keep your room cool, prevent air conditioner leakage, block hot air from entering, and save energy. For Sliding Windows: This portable AC window ventilation kit includes 4 panels. Each panel is 16.9 inches long, with a combined extension range from 16.9 to 60 inches. Fits most vertical and horizontal sliding windows. Panels can be combined in sets of 2, 3, or 4 to match your window size. Durable Construction: This AC vent kit is made of PVC material with high-temperature resistance, able to withstand prolonged exposure to hot airflow and summer sunlight, resists aging, and is reusable year after year. Easy Installation: Simple to install and remove without tools, space-saving, and suitable for use at home or in the office.