Seal made from durable fleece fabric blocks hot outdoor air from entering and keeps cooled air inside, helping portable air conditioners run more efficiently. - Compatible with common left- or right-opening tilt and casement windows and skylights. Not suitable for sliding windows or doors (left- or right-sliding windows or sliding doors). - Easy to install and remove, leaving no residue; designed for temporary use with portable air conditioners. - Ideal for cooling homes or offices where a portable AC is used to reduce heat and improve comfort. - Practical use scenarios: - Living rooms or open-plan areas where a portable AC prevents warm air from seeping in and improves overall cooling. - Bedrooms during hot nights, reducing drafts and maintaining a steady temperature. - Home offices or small workspaces where temporary, non-permanent window sealing helps stabilize the environment without permanent installation.