ThinkLites U Bent LED light bulbs are the most energy efficient in the lighting industry. At 180 lumens per watt, they use the least amount of energy in your retrofit applications. The LED fluorescent replacement is easily and safely installed. The ballast is bypassed and inserted into shunted or non-shunted sockets in the tube. Using a continuous row of LED light along the entire length, our U-shaped/U-bent T8 lamp produces an even light pattern thus eliminating dark corners/elbows.