This is the LED lightbulb used by NASA to help astronauts stay awake while aboard the International Space Station. Ideal for those prone to nod off while reading during daytime hours or those who experience Seasonal Affective Disorder (SAD) and Delayed Sleep Phase Disorder (DSPD), the bulb enhances the body’s natural alertness with a patented spectrum filter that provides blue wavelength-enriched light to suppress melatonin production in the body—the hormone that promotes sleep. The 9-watt LED yields 720 lumens of soft white light at a 65-watt equivalency and provides a 50,000-hour lifespan. For recessed light fixtures. 5 1/4" H x 4" Diam. (5 oz.)