A PAR20 bulb is named according to a standardized sizing system in which the number represents the bulb’s diameter in eighths of an inch. The “20” indicates a width of 20/8 inches, meaning the lamp measures 2.5 inches across its face. This exact dimension ensures proper fitment in recessed cans, track heads, and other fixtures designed for the PAR20 form factor.

     Most PAR20 lamps use the E26 medium screw base, the common household base type in North America. Their parabolic reflector concentrates light forward with minimal spill, producing a tight, controlled beam. This focused output makes PAR20 bulbs well suited for spotlighting, accent lighting, and narrow flood applications such as display cases, architectural highlights, and high or angled ceilings.

     Since halogen bulbs are not longer being manufactured for sale in the USA, PAR20 LED bulbs are now being manufactured. LED PAR 20 bulbs use about 10% - 25% of the energy of halogen bulbs and produce a similar light output with much less heat being produced. To see some options for PAR20 Halogen bulbs, click: LED PAR BULBS