Choose by Base

Energy saving light bulbs come in a variety of styles and bases.  The most common base is called the medium or standard base. It also goes by the official designation of E26 (or sometimes E27).  The GU24 Base is becoming more popular these days as more manufacturers make their fixtures with these bases so only energy efficient lighting can be use.  Chandeliers, sconces and other fixtures can also use the commonly referred to mini or candle base, technically called E12.  Some large CFL's will use a mogul base (E39).