A21 bulb. 3C medium base. Length 5.25. Approximate life 1,200 hours. Lamp description 30/100/RVL-1/12PQ. The light bulb that uncovers pure, true light. Filters out dull yellow rays. Makes any room look better. Reds become redder, greens become greener, and oranges become orangier. Bluish finish bulb.