Durable and safe: Made of strong polyester fabric that resists wind and regular use, providing a reliable window seal for portable air conditioners. Adjustable fit: 24–36 inches (60–92 cm) long, compatible with most portable AC units. Easily adjust to fit your window and setup. Full sealing design: Drawstring seal closes the gap to block heat transfer and prevent cooled air from leaking back into the room. Easy to operate: Remove the exhaust hose from the window opening, tighten the drawstring to seal, and open the window about 7.87 inches (20 cm) to apply sealing tape to the window frame for a secure fit. Benefits: Improves energy efficiency, reduces drafts, and helps keep the room cooler. Use scenarios: Living room: use with a portable AC to maintain a comfortable temperature on hot days. Bedroom: create a tight seal for consistent cooling while you rest. Small office or rental space: adaptable seal for non standard windows without permanent installation.