EnVision LED Bulb

A19 refers to the overall shape and size of the light bulb. The ‘A’ stands for ‘arbitrary’ and refers to the shape of the light bulb, which resembles an upside-down pear. They see use in many residential and some commercial applications.

The ‘19’ refers to the diameter of the bulb in 1/8 inch. An A19 bulb therefore has a diameter of around 19/8 or 2.375 inches.

Similar to A19 bulbs in shape, A21 bulbs offer a slightly larger size. An A21 bulb features a diameter of around 21/8 or 2.625 inches.

Even though they offer a similar size, these bulbs cannot always interchange. As long as they use the same base, an A19 may work in place of an A21, but not the other way around. Because of its larger size, A21 bulbs cannot usually fit in fixtures that require an A19.

When talking about light bulbs, A19 and E26 refer to different aspects of the bulb. A19 refers to the size and shape of the bulb while E26 refers to the size and type of the light bulb base. Though different, they may exist on the same bulb. An A19 light bulb may use an E26 base.

E26 bases, also called the medium base, is the most standard base size. The ‘E’ stands for Edison Screw, meaning they uses a threaded screw base instead of pins. The ‘26’ refers to the diameter of the base in millimeters, which means an E26 base measures around 1 inch in diameter.

An E26 base differs from other common base types, like the similar E12 candelabra base or the bi-pin GU24 base. The E12 offers a similar screw-type design but measures around 12 millimeters, or around 0.47 inches. E12 bases often see use in chandeliers or small decorative fixtures.

A GU24 base features a bi-pin connector instead of a threaded screw base. These bulbs twist-and-lock design. This base works by inserting the bulb into the matching holes in the socket and twisting the bulb until it locks into place. These bases commonly see use with CFL but can also work with LED light bulbs.

For more information about light bulb bases, check out our blog Light Bulb Fitting Guide: Light Bulb Bases and Bulb Socket Types!

Color temperature measures the color of the light emitted by the bulb in Kelvins (K). You can find an Envision LED light bulb that gives off 3000K, 4000K, or 5000K. Each color temperature works best in a different area:

• 3000K - a warm light that works well in living rooms and hospitality environments.
• 4000K - a clean, crisp light suitable for task lighting. They work well in kitchens, bathrooms, and garages.
• 5000K - a cool white light that appears similar to daylight. They work well in offices, break rooms, and retail stores.

Wattage measures the amount of electricity consumed, or used, by the light bulb. The higher the wattage, the more electricity it uses.

In the past, wattage also offered a good indicator for how bright an incandescent bulb would be. However, LEDs can provide the same amount of light while using a much lower wattage. To find out how bright a light bulb will be, look at the lumens. The higher the lumens, the brighter the bulb.

Established in 2010, EnVision LED Lighting is a Los Angeles based LED lighting leader. EnVision LED Lighting boasts a series of high efficiency, low energy consuming LED lighting products. Skillfully designed by engineers to suit a range of clients both in residential and commercial areas, their selection includes LED light bulbs, area lights, downlights, grow lights, and more.