GE's Lucalox high pressure sodium high intensity discharge light bulbs deliver high efficacy and low operating cost. They provide excellent lumen maintenance, maintaining 90% of their initial light output at 50% of the bulb life. These HID light bulbs are rated to last 24,000 hours and feature a universal burn position so they can operate in any position without affecting performance. Use this 150-Watt Lucalox ED17 shape light bulb only with S55 ballasts in open or enclosed industrial, roadway and security fixtures.