Skip to content

Plug-In Bulbs

Plug-in Light Bulbs


Here at Lighting Supply, we offer an incredible selection of light bulb types, with over a thousand varieties of the plug-in light bulb! Popular choices include the 2-pin and 4-pin bulbs, in a wide spectrum of technologies, dimensions, voltages, wattages and more, all by the leading brands you know and trust. You can easily search for the specifications you’re looking for using the convenient filters on the left side of the page. Filter your search based on the specs you need, and we’ll show you everything we have available.

Perhaps you’re not entirely sure what you need? No problem! Read on to learn some basic information about the plug-in light bulb. We explain their most popular applications, the letter/number codes used to identify them and more.

Remember — you can contact us anytime to get answers to any questions you may have. And if you’re in the market for bulk orders, check out our Volume Pricing Page! Let’s take a look at some fundamentals that will help you decide which plug-in light bulbs will work best for you.

And thank you for shopping Lighting Supply, where we help you keep your future bright.

Plug-In Light Bulb Basics
The 2-pin light bulb and the 4-pin light bulb are used for a variety of light fixtures that don’t accommodate bulbs with the Edison screw — the standard light bulb socket used throughout North America and elsewhere, recognized by the metal threads at the end of standard light bulbs.

Second in popularity only to the Edison screw, plug-in light bulbs are used throughout the world for a variety of commercial and residential applications. With 2-pin and 4-pin CFLs used in a variety of light fixtures, plug-in light bulbs offer a wide spectrum of applications throughout the home and commercial space.

Plug-in light bulbs are available in compact fluorescent, fluorescent, halogen and LED, with some varieties sporting a twist-lock mechanism to ensure proper connection. Due to the many varieties of CFL available, most of the codes related to the plug-in light bulb are designated by the letter T, for tubular, though several others are also used, including:
• FT (compact fluorescent tubular)
• FU (compact fluorescent U-bend)
• PL (compact fluorescent and LED plug-in)

Some of these designations may also include a lowercase q, indicating a quad-pin or 4-pin design. As with other bulb designations, the number following the letter indicates the distance between the pins in millimeters.

The 4-pin Light Bulb
The 4-pin light bulb variety is dominated by the CFL, with many variations available. Applications include commercial and residential, allowing the use of more efficient lighting over conventional incandescent bulbs. These bulbs, often in twin-tube and quad-tube designs, can be found in retail spaces, offices and schools, among many other locations. They come in a diverse range of wattages and color tones. With more and more LED varieties of the 4-pin light bulb becoming available, you may wish to consider the newer technology if you are looking to upgrade or save more energy.

The 2-pin Light Bulb
Similar in many ways to their 4-pin counterparts, 2-pin light bulbs are offered in both CFL and LED technologies. They offer many of the same applications as well, and are found mostly in the commercial space.

The Difference Between 2-Pin and 4-Pin Light Bulbs
The main difference between the 2-pin and 4-pin light bulb has to do with the ballast. 2-pin CFLs tend to use the older magnetic ballasts, while 4-pins use the newer, more efficient electronic ballasts.

The variety of different pin placements, layouts and spacing can seem like a major annoyance — why don’t they simply make more universal designs? The variety of connections available with plug-in light bulbs actually makes them safer, preventing their use in fixtures that aren’t meant to power them. So remember, if you’re having a difficult time installing a new plug-in light bulb, it may be because it isn’t meant to be used in your specific light fixture.

Feel free to double check with us, and we’ll help you make sure you have the right plug-in light bulb for the job!