T20-LED Bulb Series
Factory-direct T20 LED bulbs (7440/7443/W21W base) for brake, tail, turn signal and reverse lights. Canbus-ready and dual-color switchback options.
T20 LED Bulbs: 7440 / 7443 W21W & W21/5W Wedge Turn Signal, Brake & Tail Light Replacements
The T20 is the most common plastic-wedge base in modern automotive lighting, found on cars, SUVs, pickup trucks, trailers, and motorcycles worldwide. It comes in two essential configurations: the 7440 (W21W) single-contact, single-function bulb for turn signals, reverse lights, and daytime running lights; and the 7443 (W21/5W) dual-contact, dual-function bulb that combines brake and tail light, or turn signal and running light, in a single housing. MIDCARS manufactures the full T20 family in-house — standard, CANbus error-free, and dual-color switchback versions — to cover every replacement and upgrade scenario.
7440 vs 7443: What's the Difference?
The two bulbs share the same T20 wedge dimensions, so they look nearly identical — but they are electrically different. The difference comes down to the number of contacts and circuits each bulb drives.
| Feature | 7440 (W21W) | 7443 (W21/5W) |
|---|---|---|
| Base type | T20 wedge — single-contact | T20 wedge — dual-contact |
| Circuit | Single circuit (one function) | Dual circuit (two functions) |
| Brightness levels | One level | Bright (brake/turn) + dim (tail/running) |
| Typical use | Turn signal, reverse, DRL | Brake + tail combo, switchback turn + DRL |
| Common cross-reference | W21W, WY21W (amber), 7441, 992 | W21/5W, 7444, 992A |
Because both share the same wedge shape, a 7440 and a 7443 will physically fit each other's sockets — but the contact count differs. A single-contact socket drives only one function, and a dual-contact socket drives two. Always match the contact count to the socket, and check the owner's manual or the marking on the old bulb before ordering.
How to Choose the Right T20 LED Bulb
- Confirm single or dual function. One function (turn signal, reverse, DRL) = 7440 / W21W; two functions (brake + tail, or turn + running) = 7443 / W21/5W.
- Check the contact count. Count the metal contacts on the old bulb or look inside the socket — one contact is single, two is dual.
- Voltage. Standard automotive is 12V; trucks, trailers, and heavy-duty vehicles often run 24V. We build both 12V and 24V versions.
- Color temperature. 6500K white for crisp modern output, 3000K warm white for a classic halogen look, and 1800K amber for turn signals that require amber output.
- CANbus or non-CANbus. CANbus (error-free) versions include a built-in load to stop hyper-flash and dashboard warnings on vehicles with lamp-out detection; non-CANbus suits simple circuits and classic vehicles.
- Standard or switchback. Dual-color switchback versions show white as a running/DRL light and automatically switch to amber when you signal. Some switchback models use an external ACC wire for universal single/dual-filament fit, while wireless versions are built for dual-filament sockets — confirm with us before ordering.
Common Applications
- Front and rear turn signals
- Brake and tail light combinations
- Reverse / backup lights
- Daytime running lights (DRL)
- Trailer, RV, and motorcycle lighting
- 24V truck and heavy-duty vehicle lighting
Why Source T20 LED Bulbs from MIDCARS
- Factory-direct manufacturing in Dongguan, China — no middlemen, competitive wholesale pricing, and full control over quality.
- Certified compliance — CE-LVD, CE-EMC, and RoHS certificates with full test reports available to verified buyers.
- CANbus error-free versions that eliminate hyper-flash and dashboard warnings.
- Dual-color switchback options for white/amber two-in-one upgrades.
- Long lifespan and instant full brightness with low heat, ideal for continuous brake and turn-signal cycling.
- Flexible ordering — standard stock from 5 pairs; custom packaging available with a 5,000-piece packaging MOQ drawn down across repeat orders.
LED vs Halogen: Why Upgrade to LED?
LED bulbs light up instantly—critical for brake lights, where the fraction-of-a-second faster response gives following drivers more reaction time and reduces rear-end collision risk. LEDs also run cooler, last far longer than halogen filaments, draw less power, and resist the vibration and constant cycling that quickly kills halogen bulbs in turn-signal and brake duty.
Can I use a 7443 in a 7440 socket?
The two share the same T20 wedge shape, so they will physically seat — but the 7443 has two contacts and the 7440 socket has one. In a single-contact socket the 7443 will only light one function, and in a dual-contact socket a 7440 will miss the second function. Match the contact count to the socket for correct behavior.
Which color temperature is best for turn signals?
Most regions require amber output for turn signals through an amber lens or amber LED. We recommend 1800K amber for signaling, or a dual-color switchback version when you want white running light and amber turn signal in one bulb.
Do you offer 24V versions for trucks and trailers?
Yes. In addition to standard 12V versions, we manufacture 24V T20 bulbs for trucks, trailers, buses, and heavy-duty vehicles. Contact us with your voltage and application, and we will recommend the correct model.
What is your minimum order quantity?
Standard stock starts from 5 pairs for testing and sampling. For custom packaging, the packaging run has a 5,000-piece MOQ, which is pre-funded and drawn down across your repeat orders. Contact sales02@zhishanled.com for a quotation.
