What Is An A21 Bulb - These bulbs come with an e26 base, which is. A21 bulbs, on the other hand, have a marginally larger diameter of 2.625 inches and a length that is closer to 5 inches, giving them a slightly. Definition of an a21 light bulb. An a21 light bulb is a type of incandescent or led bulb that is characterized by its specific shape.
Definition of an a21 light bulb. A21 bulbs, on the other hand, have a marginally larger diameter of 2.625 inches and a length that is closer to 5 inches, giving them a slightly. An a21 light bulb is a type of incandescent or led bulb that is characterized by its specific shape. These bulbs come with an e26 base, which is.