Adjustable size: two lengths, about 300 cm or about 400 cm. Fits all sliding windows (horizontal or vertical) and works with portable air conditioners or dryers. Prevent air leakage: made from TU fabric and finished with a heatinsulating bleaching process. Blocks cold air loss while reflecting sunlight and heat outside, helping the room cool faster and reducing energy use. Complete sealing: delivers a tight, gap fit with its material and expanded firm sticker. Prevents cold air escape and keeps flies and other pests out. Enhanced detail: precise cuts and routing allow easy adjustment without distortion. Texture treatment near the outlet prevents tape from peeling after hose insertion, ensuring a seamless seal. Use scenarios: Home: slidingwindow living rooms or bedrooms cooled by a portable AC. Small office or apartment: horizontal or vertical sliders, for energy savings and pest protection. RVs, dorms, or temporary setups: reliable window sealing when venting a portable unit.