Mogul light bulbs are used with large porcelain lamp sockets that have a 1-1/2" inside diameter. These bulbs are much larger than standard size bulbs. They produce three substantial levels of light: 100, 200 and 300 watts. These mid century light bulbs gained tremendous popularity, during the 20th century, as a primary light source. Use when restoring reflector floor lamps and lamps with mogul sockets.