This 3 pack of heat and air deflectors can be used for central forced heating and cooling systems, our curved, clear plastic deflector directs air for added comfort and to save energy Sturdy polycarbonite construction comes with a lifetime 100% guarantee against breakage Held in place over your vent with powerful, permanent-strength magnets 2 3/4” tall, width adjustable from 10” to 14”; You can add up to 12” of additional width with our extension sleeve (part #67) For floor vents, direct air away from windows and furniture; For wall vents, direct warm air down during the winter and cold air up during the summer