- Energy efficient solution: Maximize energy efficiency and reduce CO2 footprint with this window seal for air conditioners. It blocks backflow, prevents hot outdoor air from entering the room, and lowers electricity use. Eco friendly and cost effective; easy to install and remove. - Windproof performance: Made from high quality waterproof polyester, the seal provides reliable windproof protection against harsh weather. - Easy installation: No drilling or tools required. Place the AC hose in the window frame, unzip, pull the seal tight, and ensure an airtight fit. - Simple temperature control: Keep the room cool in summer and warm in winter without removing the seal. Open or close the window as needed; reinstall easily for next summer. - Use scenarios: - Summer cooling in a living room: seal blocks hot outdoor air while the hose sits in the window frame. - Drafty or shared apartments: reduce energy loss while keeping the window operable. - Seasonal or rental use: install in minutes and reuse each season without tools.