Energy efficient: Save up to 78% compared to a similar lumen output incandescent bulb. Cost savings: take advantage of an estimated cost of only $1.57 a year! Best-in-class: This 4-pack of daylight twist bulbs produce a brightness of 850 lumens and a soft white color temperature of 2700K. Long-lasting: designed with a lifetime of 10,000 hours. Outdoor Rated: Use only in enclosed fixtures to avoid exposure to weather