Cleans the air . Energy efficient & helps saves money . Auto on & off . 2-Year warranty . 1.5 in. L x 2.75 in. W x 3.5 in. H Energy efficient LED night light that cleans the air. Built-in negative ion generator removes allergens such as dust, pet dander, odors, tobacco smoke and more. Saves energy and leaves indoor air fresher & cleaner. Great for asthma and allergy sufferers. Light sensor for auto on and off.