The DEFINITY PAR38 LED lightbulb from Lighting Science Group is the industry’s first LED bulb to receive the ENERGY STAR label. The bulb is 80% more efficient than the 75 watt incandescent halogen bulb it replaces, has approximately 50% more lumens (light output) than competing products, and is fully dimmable. The DEFINITY PAR38 bulb is the first in a line of Lighting Science Group products going through the ENERGY STAR approval process; the line includes A19, PAR30, PAR20, MR16, and G25 bulb types. To ensure both performance and reliability, the cULus-listed DEFINITY LED line was tested under the ENERGY STAR Eligibility Criteria, Version 1.1 process by an independent laboratory approved by the U.S. Department of Energy’s CALiPER program. To receive the ENERGY STAR label for an integral LED lamp, the DEFINITY PAR38 bulb was tested at a third party laboratory under the LM79 standard for overall efficiency, color temperature, color rendering, color spatial uniformity, and light emission pattern. Additional testing required for ENERGY STAR approval included: rapid cycle thermal stress testing, in-situ temperature testing, both lumen maintenance and color maintenance testing, and an operational test for 3,000 hours at elevated ambient temperature. It comes with a five-year limited warranty.