These are going to be the type of small CFLs that you might use in the home. Because so many people are still using incandescent light, and they have lamps and fixtures that use the lights, there was a need for these newer fluorescent lamps to use retrofitting in order to be able to work. They have the same screw in base that you use with the regular light bulbs that you used to have. The retrofitted lamps mean that people do not have to go out and buy all new fixtures just so that they might be able to use the CFLs in the home. This is a huge benefit.