We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Ten triple-tube compact fluorescent bulbs with four-pin bases in a pack

SYLVANIA

SYLVANIA 21105 38W 4100K GX24q-4 10 Pack Light Bulb

SKU CH-N0BK-9GJRZ

Pack of ten 38-watt triple-tube fluorescent bulbs with GX24q-4 bases, 4100 K cool white output and 18 000-hour rated life

  • TypeFluorescent Tubes
  • Watts38
  • 10-bulb pack simplifies multi-fixture projects
  • 38 W delivers 2 500 lumens of cool white light
  • 4 100 K colour temperature suits task and general lighting
  • GX24q-4 four-pin base fits compatible electronic ballasts
  • 18 000-hour average life reduces replacement frequency

Product identity

This SYLVANIA 21105 pack contains ten 38-watt compact fluorescent lamps rated at 4,100K cool white. Each bulb uses a GX24q-4 four-pin base and delivers 2,500 lumens with an 18,000-hour average lifetime. The triple-tube amalgam design suits commercial fixtures that require electronic rapid-start operation.

Compatibility check

Verify that the fixture accepts a GX24q-4 four-pin base and runs an electronic rapid-start ballast before ordering. The lamps are not dimmable and will not operate on magnetic or instant-start ballasts. Ensure the housing accommodates the triple-tube T11 form factor and that the circuit can support the 38-watt load per bulb.

Build and daily use

The Supersaver Ecologic construction uses amalgam technology for stable output across temperature changes and reduced mercury content. Four-pin bases key into matching sockets to prevent incorrect insertion during maintenance. Rated for 18,000 hours, the pack of ten simplifies relamping schedules in offices, retail spaces or institutional ceilings where consistent cool-white light is required.

Highlights

  • 10-bulb pack simplifies multi-fixture projects
  • 38 W delivers 2 500 lumens of cool white light
  • 4 100 K colour temperature suits task and general lighting
  • GX24q-4 four-pin base fits compatible electronic ballasts
  • 18 000-hour average life reduces replacement frequency

Specifications

TypeFluorescent Tubes
BrandSYLVANIA
Watts38

Questions about this item

What is included in the 10-pack and does it require a separate ballast?

The pack contains ten 38-watt triple-tube bulbs with GX24q-4 4-pin bases. They are designed for electronic rapid-start ballasts, which are not included and must be supplied by the fixture.

How do I choose between the 38-watt 4100K version and other wattages or colour temperatures?

Select this 38-watt, 4100K cool-white model when your fixture specifies a CF42DT/E/IN/38W/841 lamp and a GX24q-4 base; different wattages or colour codes will not fit or will change the light appearance.

What does the 2500-lumen rating mean once the bulb is installed in a compatible fixture?

In a matching electronic rapid-start fixture the lamp delivers approximately 2500 lumens of 4100K cool-white light and is rated to maintain output for an average of 18000 hours.

Also in this aisle

People compared these

Same shelf, same checkout — eight coins and a 30-minute rate lock.