F21T5/841 - 21 Watt 34 Inch T5 Fluorescent Light Bulb - 4100K Cool White - 2100 Lumens - 36,000 Hours

The F21T5/841 is engineered for longevity and clarity. Featuring a thicker, protected filament design, it resists end blackening and maintains steady light output throughout its life. With a 90 CRI rating, it delivers a full, vibrant spectrum of light—making it ideal for offices, retail, or any space where color clarity and performance matter. Reliable, efficient, and built to outperform standard tubes.

Specs

SKU
F21T5/841
Bulb Shape
T5
Wattage
21W
Color Rendering
80
Power Voltage
120-277V
Dimmability
Dimmable
Color Temperature
4100k
Base Code
G5
Base Type
Miniature Bi-Pin
Life Hours
36000
Lumens
2100
Contains Mercury
Yes
Shatter Guard
No
UL Listed
Yes
Length
34 Inches
Width
0.625 inches
Height
0.625 inches

A BRIGHTER WORLD

Regular price $172.73
Regular price Sale price 172.73
($4.31 per bulb)
Sale Sold out
QTY
Qty:
ASK AN EXPERT ? ?

If you have any questions, chat with a Lumen Master, we are lighting specialists who enjoy talking about light bulbs, long walks in the park, early-morning yoga, and late-night guitar hero jam sessions.

*** Returns are expensive & time consuming, chat with a Lumen Master to confirm you made the right choice.

Free Shipping
Bulb Recycling Program

Specs

SKU
F21T5/841
Bulb Shape
T5
Wattage
21W
Color Rendering
80
Power Voltage
120-277V
Dimmability
Dimmable
Color Temperature
4100k
Base Code
G5
Base Type
Miniature Bi-Pin
Life Hours
36000
Lumens
2100
Contains Mercury
Yes
Shatter Guard
No
UL Listed
Yes
Length
34 Inches
Width
0.625 inches
Height
0.625 inches

About

GoodBulb F21T5/841 21W Fluorescent Light Bulb: Legacy Cool White Clarity
34-inch T5 Fluorescent Light Bulb with a miniature bi-pin G5 base. Emitting 2,100 lumens at 4100 Kelvin Cool White, this slim-profile lamp delivers bright, clean light—ideal for task lighting, commercial spaces, healthcare environments, and utility fixtures. With a 36,000-hour rated life, it’s designed for consistent, long-term performance with minimal maintenance.

Why 4100K Cool White?
The 4100K color temperature delivers a bright, neutral tone that enhances focus and visibility—ideal for task-heavy and high-traffic environments.

✔ Offices & Classrooms – Promotes productivity with crisp, clear illumination.
✔ Medical & Laboratory Spaces – Provides accurate light for precision work.
✔ Workshops & Utility Rooms – Keeps workspaces well-lit without harsh glare.

High Output. Low Profile. Long Life.

✔ 2,100 Lumens of Bright Light – Efficiently lights up compact areas.
✔ 36,000-Hour Rated Life – Reduces downtime and replacement frequency.
✔ Slim T5 Form Factor...

READ MORE
View full details
image_02

Talk to a Lumen Masters

A Lumen Master at GoodBulb is a trained lighting specialist who cares more about helping others than just making sales.

They understand that purchasing light bulbs is not easy and there are more bulbs than you can imagine. Start shopping for light and if you have questions we are here to help.