This 6 watt LED PAR 20 LED bulb is a direct replacement for a 40 watt spot or flood light. It has a standard E-26 screw type base and fits many track lights and small pot lights. Three high power 2 watt Edison LEDs are housed in an rigid aluminum body that contains no delicate filaments. With a lifespan of 50,000 hours you can leave them on for 12 hours a day and they will last for 12 years. Your electrical cost ( .09/kw) with this light on for 12 hours a day is only $0.19 per month. This bulb is not dimmable.