Parabolic aluminized reflector (PAR) 30 bulbs control light more precisely. They produce about four times the concentrated light intensity of general service A shape incandescents, and are used in recessed and track lighting. Like all light bulbs, the 30 value represents the diameter of the bulb in 1⁄8 of an inch. Therefore, PAR 30 types are short light bulbs that are 3.75 inches in diameter. PAR30 LED Replacements: PAR30 and PAR30 LED short neck bulbs are some of the best applications for LED due to its directional nature. LED PAR30 provide similar output and beam profile characteristics while using only a fraction of the power.