The Medlight 2401 delivers 10,000 lux of full spectrum light and can be effective as larger units costing twice as much or more. The Medlight™ 2401 reduces the symptoms of SAD - excessive sleep, social withdrawal, weight loss and melancholic depression. The Medlight™ 2401 Light Box is made in the USA with the same quality craftsmanship as it's larger version, Model 2400. It's construction is all-metal and comes equipped with lamps, a U.V. shield, rubber feet and on-off switch. The size is only 10 1/2 in. x 9 1/2 in. x 3 1/4 in. and weighs only 5 lbs.