2D 21 watt fluorescent light bulbs are different from circular bulbs in that they have a more rectangular shape. If you have a light fixture that has these, you won't be able to use any other kind of light bulb in it's place. It's a really unique light bulb and comes in several wattage although the wattage are not interchangeable. The color is a warm color temperature appearance so it works well in homes and in multi-housing unit's to give a comfortable inviting appearance. It has a ballast that operates the 2D 21 watt fluorescent light bulbs only. This is the lowest wattage available in this variety of light bulb. It's not something commonly used but many people see it in small light fixtures where they have something surface mounted usually. These do have a long life of 10,000 hours and should be able to last for years in a home lighting situation. The color is made to be very much like incandescent color and there are no choices other than that. It makes things like woods and earth tones really stand out by giving it that standard warm color. The base does have a 4 pin configuration and that has a special kind of socket that it plugs into. There is only one kind of lamp that can be used in this situation and you need to make sure that the wattage you have is the same as the ballast that runs it.

 

Product features:
- 21 watts.
- A kind of square shape.
- 4 pin socket connection.
- 2D 21 watt fluorescent light bulbs operate on an electronic ballast.