This is the larger version of what people have come to know as standard size light bulbs. These are the A21 bulbs which you might be familiar with, the ones you've probably bought for years in hardware stores except these have a slightly larger bulb and a little longer neck.  The "A" shape was one of the first designs and continues to still be the one most people use.  They fit in almost any light fixture, but one of the most common places that it's used are in table lamps and sconce lighting.  It has a standard medium base and screws into sockets that are made for all kinds of US lighting.  Although it's popular and inexpensive, it's not always the proper light bulb to be using.  First of all, the A21 light bulbs have no light control associated with them, so it's important to select the right fixture.  If you desire greater light control, then perhaps you might need a incandescent flood light instead.  This will get you a directed beam of which is more controlled.  But sometimes people put them in deeper reflector cans which will fit while directing the light produced by the lamp.

Incandescent lamps are the type that were developed earliest of any of the other kinds and these developed into what we know as the A19, then came the larger A21.  There are several different varieties of these lamps in this shape which include long life bulbs, Daylight plus, clear, frosted, soft pink and the ever popular soft white.  The soft white bulbs are the ones most commonly used for reading and table lamp fixtures.  It's a long history with this lamp and most of the improvements have come with longer life versions of these.  The standard 3 way soft white is usually this A21 light bulb size.  The long life A21 light bulbs are the same physical size but have multiple filament supports that protect against vibration and rough use.  In fact, these are sometimes called rough service light bulbs.  You might be familiar with trouble lights in the automotive service industry, they usually use these longer life light bulbs because they won't go out all the time when roughly handled.  The latest innovation has been the compact fluorescent in an A21 shape.  Now you can achieve the same look of a regular light bulb while saving energy.  There is no sacrifice of light output either, making it the perfect replacement.

Lately, people have been concerned about the kind of like that they're working under or living under.  That's why so many people are turning to what is called full spectrum lighting. The term full spectrum is most often used when referring to fluorescents that simulate natural outdoor light. By definition, virtually all fluorescent light bulbs are full spectrum in that they contain some of all colors in their spectral range. Full spectrum fluorescents are a great option to get better natural lighting, but so are the incandescent full spectrum. But the Sylvania Daylight A21 light bulbs aren't a fluorescent bulb and therefore don't have the same type of light as fluorescent. It's an incandescent with special coatings that has the warmer tones filtered out. However, the term full spectrum is primarily used when referring to those lamps that fall into the white to blue/white color temperature range.  Most of their Daylight incandescent light bulbs use a blue phosphor coating which you can see when you look at it unlit. The variety ranges from standard A21 bulbs to halogen called Daylight.

If you've decided on ServiceLighting.com, you've made an excellent choice for good lighting and you're in good company. From your local retailer to finer homes to warehouse lighting, you will most likely find these A21 light bulbs lighting your way. Remember that there are many types of bulbs, we describe just some of the most common used in home and commercial lighting here.  Whatever type you choose or have, you will be getting the highest quality and the most light you can for your money.  If you need help identifying a bulb, our customer service representatives can help you determine what you have.