We are often asked which LED bulb is the best to put in a 4" pot light. Our recommendation is this 9W PAR20 which will replace the hot halogen PAR20 bulbs you are currently using. The bulb diameter is the same so this bulb will fir into whatever style trim you are using. With three high power CREE LEDs you get a great replacement for a 50W halogen.
Made with a standard E26 medium base this bulb is also often used as a replacement bulb in track lights. 50,000 hour life, dimmable and earth friendly.