Halogen Par 20 bulb only
Green Energy Lighting Company halogen par indoor/outdoor spotlight Par 20 120V 50W
39 Watt High-Efficiency PAR20 replaces the 50 Watt Standard PAR20
The diameter of a PAR halogen is measured in eighths of an inch. The number after PAR is that measurement. For example, PAR20 is 20 eighths of an inch or 20/8 = 2.5 inches.