Keep your room cooler and reduce energy costs This air conditioner window seal blocks backflow and prevents hot outdoor air from entering the room around your portable AC exhaust hose. By stopping unwanted heat and leakage, it helps your unit cool more efficiently and can lower electricity use. Durable, weatherproof construction Made from reliable polyester material, the seal is waterproof and windproof so it holds up in all weather while maintaining a tight barrier around the hose and window frame. Easy, tool-free installation No drilling or special tools required. Install in minutes: position the exhaust hose, open the zipper, tighten the seal around the hose, and attach to the window frame for an airtight fit. Designed for portable air conditioners Specifically built to work with portable AC exhaust hoses and window frames, providing a practical, removable seal when you run a portable unit. Year-round convenience Leave the seal in place through the year if you prefer—open or close your window in any weather without removing it. When needed, removal and reinstallation the following season are quick and simple. Key attributes Function: blocks hot air backflow and seals around portable AC exhaust hose Compatibility: made for portable air conditioners and window-frame installation (hose passes through zipper) Material: durable, waterproof polyester Performance: windproof and airtight fit to improve AC efficiency and reduce heat transfer Simple installation steps 1. Place the portable AC exhaust hose through the seal. 2. Open the zipper and position the seal against the window frame. 3. Tighten the seal around the hose and secure it to the frame for an airtight fit. 4. Remove or reposition easily when needed—no drilling or tools required. Practical use scenarios Bedroom: Keep sleeping spaces cooler at night while preventing warm outdoor air from entering. Home office: Maintain a consistent, energy-efficient workspace during hot days. Small apartment or rental: Add a removable, non-permanent seal for portable AC units without modifying windows or frames. Reliable, straightforward protection for portable air conditioners—improves cooling performance, resists weather, and installs in minutes.