Reflector (R) or Bulged Reflector (BR) 30 bulbs have a reflective coating on the inside of the bulb that directs light forward. Flood types (FL) and led floodlight bulbs spread light. Spot types (SP) concentrate the light. Reflector (R) bulbs put approximately double the amount of light (foot-candles) on the front central area as General Service (A) of same wattage. Like all light bulbs, the 30 value represents the diameter of the bulb in 18 of an inch. Therefore, a R30 is 3.75 inches in diameter.