Compact fluorescent lamps (CFLs) are single-ended, pin-based lamps used in luminaire/fixture systems. CFLs are available in a wide variety of shapes including twin tube, quad tube, triple tube, and square (2-D). Compact fluorescent lamps utilize several different base configurations, which require an appropriate ballast to operate the lamp effectively.  To maximize lamp life and fixture safety a program start ballast with Robertson's patented EOL protection should be used.