The direct replacement tubes (Type A) and ballast bypass tubes (Type B) both have tiny little drivers inside the tube. Those have 3 major drawbacks. The biggest is they can’t shed the heat so they end up failing prematurely. If you read the warranty fine print you’ll see that these lights are only designed to be used for 3 hours a day. The second biggest disadvantage is that these are much less efficient. You take a 10-20 lumens per watt hit in efficiency. The third is if the light doesn’t fail then over time it may start to discolor in one spot in the tube. That’s where the driver is.