Just to barge in on the LED conversation before Jack gets it back on track for the car:
If you take Ken's link you'll see it says "two sided connection". There are essentially two types of replacement tubes, either powered from two ends as this reference, or one end. The two end is what you use if just removing the existing tubes because the ballast powers from two ends. It's better to take the ballast out to enjoy the energy savings, which might require some short or replacement lengths of wire to make up for the ballast removal. The other alternative with the single end would necessitate buying the non-shunted tombstone ends referenced lower in the Amazon ad, these have no wires going to them as the single ended ones power at the one end only. Just something to be aware of if you would like to make the switch. Another thing to watch for is some of those big box store complete fixtures don't have replaceable lamps. LEDs are known for long, long life so that might not become an issue, but I've had one lamp in one of the fixtures I put in a year ago lose two of the individual diodes so it lost a small amount of light output. The place I bought it from replaced it, but that might not have happened had some time passed. I prefer replaceable lamps, and hope to get the life expected so I won't have to replace them.