We have a lot of old fluorescent tubes in outside buildings. The fittings for most of these are decades old and really need replacing. I have bought a couple of these LED fittings to see if we can use them as replacements. The one linked is a direct replacement for a 5ft tube.
They have a three-year warranty and subjectively the level of illumination is much better than the equivalent tube. Claimed electricity consumption (not checked yet) is less than the 90W tubes they are replacing. An important factor if you have nearly a hundred of the old ones!
Unlike the old tubes, which struggle to start if they are old, or it's cold these come on instantly.