Frost King 15 in. to 25 in. Adjustable Heat and Air Deflector is designed to enhance the efficiency of air flow throughout your home. This versatile deflector is compatible with central forced air systems and adjusts easily from 15 inches to 25 inches to fit various vent sizes. It features strong permanent magnets that securely hold the deflector in place over your vents, while an integrated filter helps remove dust particles from the air, contributing to cleaner indoor air quality. For optimal performance, point the deflector downward during winter to improve heating and upward during summer to enhance cooling. When used with floor vents, it is to direct air away from windows or furniture to maximize comfort and effectiveness. Model Number: HD11