Circular fluorescent tubes are going to be useful for certain types of fittings. As the name suggests, these are tubes shaped into a circle. They work on the same principles as a traditional linear tube. You will find that the same companies that are making the linear tubes often have the circular variety as well. One of the key benefits to this type of tube is that you will often be able to get much more illumination out of a smaller space and fitting. The round tube can fit into a smaller space, but because it is basically a bent linear tube, it is able to provide more light. They are going to be useful in a variety of different applications at home and other locations.