R20 reflector light bulbs are a great choice for track lights and 4 inch recessed can fixtures. The Halco 10100 R20FL45 bulb is equipped with a heavy-duty 130 volt filament, allowing it to last longer when operated at 120 volts. This Halco bulb operates at 45 watts, has a medium (E26) base, and a 3,000 hour life span.