Not every light bulb screws into a socket.

Some of the brightest and most versatile lamps use a completely different design. Instead of a threaded base, they feature electrical contacts on both ends of the bulb. These are known as R7S linear lamps, and they’ve been a staple in residential and commercial lighting for decades.

If you’ve ever replaced the bulb in a floor torchiere lamp, outdoor floodlight, work light, or decorative wall fixture, there’s a good chance you’ve encountered an R7S lamp.

Today, modern LED replacements offer dramatically improved energy efficiency while maintaining the same compact size and light distribution.

At Unique Lighting & Home Decor, we regularly help customers identify these specialty lamps and choose the correct replacement. Here’s what every homeowner should know.

What Is an R7S Light Bulb?

The R7S designation refers to the base, not the shape of the lamp.

An R7S bulb has:

Electrical contacts on both ends
A recessed-contact (“R”) base
A 7 mm contact spacing design (“7S”)
A long, narrow linear profile

Because electricity is supplied from both ends, R7S lamps are often called:

Double-ended lamps
Linear lamps
J-type bulbs
Linear halogen bulbs

The bulb is held in place by spring-loaded sockets at each end.

What Does T3 Mean?

Many R7S lamps are also identified as T3 bulbs.

The T stands for Tubular, describing the shape of the lamp.

The 3 refers to the approximate diameter of the glass tube in eighths of an inch.

So while R7S identifies the base, T3 describes the shape.

Both designations are important when selecting a replacement.

Understanding the Model Number

A model such as:

6W/LED/T3/78MM/830/120V/D R7S

contains a surprising amount of information.

Here’s what it typically means:

6W – 6 watts of power consumption
LED – Light Emitting Diode technology
T3 – Tubular bulb shape
78MM – Overall lamp length (78 millimeters)
830 – 80+ CRI with a 3000K Soft White color temperature
120V – Operates on standard household voltage
D – Dimmable
R7S – Double-ended R7S base

Once you understand the naming convention, replacing these lamps becomes much easier.

Where Are R7S Bulbs Used?

Although not as common as household bulbs, R7S lamps are found in many applications.

Common uses include:

Torchiere floor lamps
Outdoor floodlights
Security lighting
Work lights
Construction lighting
Decorative wall sconces
Landscape lighting
Display lighting
Commercial accent lighting
Hospitality fixtures

Because they’re capable of producing significant light output in a compact package, R7S lamps have been especially popular where space is limited.

Halogen vs. LED R7S Bulbs

For many years, nearly every R7S lamp was halogen.

Today, LED technology offers a better alternative for most applications.

Feature	Halogen R7S	LED R7S
Energy Consumption	High	Much Lower
Heat Production	Very High	Much Lower
Lifespan	Approximately 2,000 hours	Often 15,000–25,000+ hours
Brightness	Excellent	Excellent
Maintenance	Frequent replacements	Minimal replacements

For homeowners, the most noticeable difference is usually heat.

Traditional halogen R7S lamps become extremely hot during operation.

LED replacements remain significantly cooler while using only a fraction of the electricity.

Choosing the Correct Length

One of the most important things to verify is the length of the lamp.

The two most common R7S sizes are:

78 mm

Often found in:

Small wall sconces
Decorative fixtures
Compact floodlights
Accent lighting

118 mm

Common in:

Torchieres
Outdoor security lights
Larger work lights
Commercial fixtures

Although the bulbs look nearly identical, they are not interchangeable.

Always measure your existing lamp or check the fixture specifications before purchasing.

Understanding Color Temperature

LED R7S lamps are available in several color temperatures.

2700K

Warm White

Excellent for living rooms and decorative lighting.

3000K

Soft White

One of the most popular residential choices.

Perfect for:

Wall sconces
Torchieres
Accent lighting

4000K

Cool White

Ideal for:

Workshops
Utility rooms
Task lighting

5000K

Daylight

Often selected for:

Security lighting
Garages
Outdoor work areas

Are R7S LED Bulbs Dimmable?

Many modern R7S LED bulbs are dimmable—but not all.

Before purchasing a replacement, verify:

The bulb is labeled dimmable.
Your dimmer is compatible with LED technology.
The fixture is approved for LED replacement lamps.

This helps prevent flickering or limited dimming performance.

Common Mistakes Homeowners Make

Buying the Wrong Length

The lamp may look correct but be too short—or too long—to fit the fixture.

Always verify whether your fixture uses a 78 mm or 118 mm lamp.

Choosing Brightness by Wattage

Modern LED bulbs should be selected by lumens, not watts.

A 6-watt LED can often replace a much higher-wattage halogen lamp.

Ignoring Enclosed Fixture Ratings

Some R7S lamps are installed inside enclosed fixtures.

Always confirm that the LED replacement is approved for enclosed applications if required.

Forgetting About Dimming

Not every LED replacement is dimmable.

If your fixture uses a dimmer, verify compatibility before purchasing.

Showroom Tip

One of the easiest ways to identify an R7S replacement is to bring your old lamp into our showroom. If the markings have faded, simply measuring the overall length, usually 78 mm or 118 mm, can quickly narrow down the correct replacement.

Why LED Is the Best Upgrade

For most homeowners, replacing an older halogen R7S bulb with an LED version offers immediate benefits:

Lower electric bills
Much less heat
Longer life
Fewer bulb changes
Excellent light quality
Better efficiency

It’s one of the easiest lighting upgrades you can make without replacing the fixture itself.

Visit Unique Lighting & Home Decor

Specialty bulbs don’t have to be difficult to identify.

At Unique Lighting & Home Decor, we help homeowners, electricians, contractors, and business owners find replacement lamps every day.

Whether you’re replacing a torchiere bulb, upgrading outdoor floodlights, or searching for a hard-to-find R7S lamp, we’ll help you choose the correct replacement based on the length, brightness, color temperature, and application.

Visit us at:

Unique Lighting & Home Decor
926 S. Arizona St.
Butte, MT 59701

If you’ve never wandered through our showroom, you should.

Bring your old bulb—or simply take a photo of the fixture—and let our lighting experts help you find the right replacement the first time.

References (APA 7th Edition)

National Electrical Manufacturers Association. (2020). ANSI C81 Series: Lamp Bases and Holders.

U.S. Department of Energy. (n.d.). LED Lighting. https://www.energy.gov/energysaver/led-lighting

ENERGY STAR. (n.d.). Light Bulbs. https://www.energystar.gov/products/light_bulbs

International Electrotechnical Commission. (2017). IEC 60061: Lamp Caps and Holders Together with Gauges for the Control of Interchangeability and Safety.

R7S LED Light Bulbs Explained: Everything You Need to Know About Double-Ended Linear Lamps