Luxrite Twin Tube Compact Fluorescent Bulb Uses 75% less energy then equivalent incandescent lamps. It has a long life of 20,000 Hours and it works with all 2G11 4-pin sockets. Similar replacement to Sylvania 20585 FT40DL/835/RS/ECO, Philips 300434 - PL-L 40W/35/RS/IS.