W21W (7440) Super Canbus Red LED Brake & Fog Light Bulbs 18W 300LM Fan Cooled

W21W (7440) Super Canbus Red LED Brake & Fog Light Bulbs 18W 300LM Fan Cooled

Upgrade your vehicle's original W21W (7440) filament bulbs with these premium Super Canbus Red LED replacements. Producing a strong 300-lumen red output, these single-intensity LED bulbs are designed for compatible brake light, rear fog light and other red vehicle-lighting applications.

Each bulb combines automotive-grade LED chips, an intelligent Super Canbus driver and an integrated high-speed cooling fan to provide instant illumination, efficient heat dissipation and improved compatibility with modern vehicle electrical systems.

Key Features

• Super Canbus W21W (7440) Red LED Bulbs
• Direct replacement for compatible single-intensity bulbs
• Strong 300-lumen red output
• 18W power output per bulb
• Pure red LED light
• Suitable for compatible brake and rear fog light applications
• Automotive-grade LED chips
• Built-in intelligent Super Canbus driver
• Designed to reduce bulb-warning messages and flickering
• Integrated high-speed cooling fan
• Aviation-grade aluminium construction
• 360° light distribution
• Plug & Play installation
• Non-polarity design
• Instant illumination
• Energy-efficient operation
• Over 40,000-hour lifespan
• Supplied as a pair

Designed for Single-Intensity Red Lighting

The W21W (7440) is a single-intensity wedge bulb designed to perform one lighting function. It operates at full output whenever the relevant vehicle circuit is activated.

This red version is suitable for compatible brake lights, stop lights, rear fog lights and selected auxiliary lamp positions requiring a red W21W or 7440 bulb.

It is not a dual-intensity brake and tail light bulb and should not be used as a replacement for a W21/5W (7443) bulb.

Pure Red LED Output

These bulbs generate red light directly from the LED chips instead of relying on white light passing through a coloured lens.

This produces a rich, clearly defined red output that is suitable for compatible clear or red lamp housings requiring a dedicated red bulb.

A colour-matched red LED can also produce a cleaner and more consistent appearance through a red lens than a white LED replacement.

Fast Brake Light Response

LED technology reaches full brightness almost instantly when electrical power is applied. When used in a compatible brake light position, this provides a faster and sharper response than a conventional filament bulb.

The immediate illumination helps make braking intentions more noticeable to following drivers and gives the rear lighting a modern appearance.

Intelligent Super Canbus Technology

Each bulb incorporates an intelligent Super Canbus driver designed to minimise dashboard bulb-warning messages, flickering, shut-off issues and electrical interference on many modern vehicles.

Whilst compatible with most Canbus systems, some vehicles with particularly sensitive bulb-monitoring circuits may still require an additional load resistor or Canbus decoder.

Advanced Active Cooling

A built-in high-speed turbine cooling fan continuously draws heat away from the LED chips, helping maintain stable light output during prolonged operation.

The fan works with the CNC-machined aviation-grade aluminium housing to provide efficient heat dissipation and support reliable long-term performance.

360° LED Light Distribution

The multi-sided LED chip arrangement produces wide and even illumination throughout the lamp reflector.

This design helps replicate the position of the original filament, supporting consistent red light distribution and visibility from different viewing angles.

Ideal Applications

• Brake Lights
• Stop Lights
• Rear Fog Lights
• Rear Auxiliary Lights, vehicle dependent
• Clear lamp units requiring a red bulb
• Red lamp units requiring a W21W replacement
• Any compatible application requiring a W21W bulb
• Any compatible application requiring a 7440 bulb
• Any compatible application requiring a W3x16d wedge base

Technical Specifications

W21W, 7440 and W3x16d Compatibility

W21W and 7440 are commonly used references for the same single-intensity automotive wedge bulb.

These bulbs use a W3x16d wedge base and operate at one brightness level. They are not interchangeable with dual-intensity W21/5W (7443) bulbs, even though the bulb bodies can appear similar.

Please remove and inspect your existing bulb before ordering. Compare the wedge base, electrical contact arrangement and original bulb reference to confirm compatibility.

W21W and W21/5W Are Different

A W21W (7440) bulb is single intensity and performs one lighting function. A W21/5W (7443) bulb is dual intensity and provides separate high and low brightness levels.

The red W21W version is therefore suitable for single-function brake or rear fog applications, but it cannot provide combined brake and tail light operation.

Package Contents

• 2 × Super Canbus W21W (7440) Red LED Bulbs
• Retail Presentation Box

Important Information

• Please check your existing bulb type and base before ordering.
• Designed for vehicles requiring W21W (7440) W3x16d single-intensity bulbs.
• Please confirm that a red bulb is suitable for the intended lighting function.
• Suitable for compatible brake light and rear fog light applications.
• Not suitable as a replacement for W21/5W (7443) dual-intensity bulbs.
• Do not order solely by vehicle make, model or registration number.
• Canbus compatible with most vehicles.
• Some vehicles with highly sensitive bulb-monitoring systems may still require additional resistors or decoders.
• Suitable for 12V vehicle electrical systems.
• Please ensure sufficient clearance inside the lamp housing for the fan-cooled bulb body.
• Road-use legality depends on the vehicle, lamp unit and intended application.

Why Buy from HIDS-DIRECT?

HIDS-DIRECT specialises in premium automotive lighting products, supplying high-quality LED upgrades trusted by thousands of customers across the UK.

Every product is carefully selected for performance, reliability and ease of installation, helping you upgrade your vehicle with confidence.

Frequently Asked Questions

Will these W21W red LED bulbs fit my vehicle?

These bulbs are designed for vehicles that use a W21W (7440) bulb with a W3x16d wedge base. Please remove and inspect your existing bulb, consult your vehicle handbook or compare the base before ordering.

Are W21W and 7440 the same bulb type?

Yes. W21W and 7440 are commonly used references for the same single-intensity automotive wedge bulb.

What is the difference between W21W and W21/5W?

W21W (7440) is a single-intensity bulb with one brightness level. W21/5W (7443) is a dual-intensity bulb with separate high and low outputs. They are designed for different applications and are not directly interchangeable.

Can these bulbs be used as brake lights?

Yes, provided your vehicle uses a W21W (7440) bulb for the brake light function. Please check the original bulb type and lamp configuration before ordering.

Can these bulbs be used as rear fog lights?

Yes, provided your vehicle uses a W21W (7440) bulb in the rear fog lamp. The dedicated red output makes them suitable for compatible rear fog light applications.

Can these bulbs provide both brake and tail light functions?

No. W21W is a single-intensity bulb and provides only one brightness level. A vehicle requiring combined brake and tail light operation normally uses a dual-intensity W21/5W (7443) bulb.

Can these bulbs be used behind a clear lens?

Yes, provided the lamp requires a red W21W bulb. The LED chips generate red light directly, making them suitable for compatible clear lamp units.

Can these bulbs be used behind a red lens?

Yes, provided the bulb type and electrical specifications are compatible. A dedicated red LED can produce a rich and clearly defined colour through a red lens.

Are these bulbs Canbus compatible?

Yes. They include built-in Super Canbus electronics designed to reduce dashboard bulb warnings, flickering and shut-off issues on many vehicles. Some particularly sensitive vehicles may still require an additional resistor or decoder.

Are these bulbs polarity sensitive?

No. They use a non-polarity design, allowing them to operate regardless of the positive and negative electrical orientation within a compatible socket.

Do these bulbs have a cooling fan?

Yes. Each bulb contains an integrated high-speed turbine fan that helps remove heat from the LED chips and maintain stable performance during prolonged use.

Do I need to modify the wiring?

No. These bulbs are designed as a direct Plug & Play replacement for a compatible W21W (7440) socket. No rewiring or coding is normally required.

How many bulbs are supplied?

This product is supplied as a pack of two red W21W LED bulbs.

Are these red LED bulbs road legal?

Road-use legality depends on the vehicle, lamp unit and intended function. LED retrofit bulbs may not be approved for every exterior lighting application, so please check the relevant vehicle-lighting regulations before installation.