The Philips Master PL-L CFL bulbs have a high light output and provide optimum light performance with a much more efficient use of energy compared to the conventional incandescent bulb! A Philips PL energy saving light bulb can save up to 80% energy while emitting the same light output as an incandescent bulb. The PL-L energy saving light bulbs come with a 4-pin base which means that they must be used with an electronic ballast. Are you looking for a Philips PL-L energy saving bulb that is dimmable? Budgetlight has multiple dimmable bulbs!