Lux The AirFlow Breeze Home Heating/Cooling System (Brown) (Fits 4" W x 10" L opening) The Brown AirFlow Breeze Home Heating/Cooling System discretely warms or cools your house by pulling the remaining hot/cold air from your vents. Letting your central heating system shut off sooner and keeping your temperature comfortable for longer Easy installation against any standard 4 by 10 vent opening, works for most households Switch between two high functioning cooling or heating modes for year round use Safe for children and pets due to low voltage operation No tools necessary