Product Specifications

4U16 Series SMD Dual Color Switchback LED Bulbs 1157 3157 7443

The 4U16 series is designed for drivers and installers who want one bulb to handle both daytime running light and turn signal functions with a clean modern look. Each bulb combines a bright white running light with a vivid amber indicator inside a compact alloy housing. With 16 pieces of 3030 SMD LEDs and a carefully matched driver, the bulbs deliver about 560 lumens of white light and 480 lumens of amber light while working on standard 9–18 V DC automotive systems. Three base options, 1157, 3157 and 7443, make it easy to match common front combination lamp sockets across different vehicles.

Switchback White and Amber for DRL and Turn Signal

In normal driving the white LEDs are active so the lamp works as a crisp daytime running light or position light at the front of the vehicle. When the turn signal is triggered, the amber LEDs take over and provide a clear flashing indication that stands out from the surrounding lighting. After the signal is cancelled, the bulb returns automatically to white operation. This switchback behavior keeps the front end neat and stylish without sacrificing the clear color contrast that helps other road users see your intentions quickly.

High Output from 16 Pieces of 3030 SMD LEDs

At the core of each bulb is a compact array of 3030 SMD packages, eight pieces for white and eight for amber. These LEDs are built on PPA material and are chosen for high luminous efficacy and stable color performance. By sharing the total output across multiple chips, the design keeps each LED working within a comfortable range, which supports long life and steady brightness. The white section delivers a strong, neutral output suitable for DRL use, while the amber section is tuned to maintain deep color even when viewed through tinted or aged lamp lenses.

Aluminum Circuit Board for Fast Heat Transfer

The LEDs are mounted on an aluminum circuit board rather than a traditional fiberglass board. Aluminum has much higher thermal conductivity, so heat moves away from the LED junctions more quickly. This improves thermal balance across the whole light source and helps prevent localized hotspots that can lead to color shift or early failure. For workshops and fleet operators this means fewer comebacks and a more predictable service life, even in vehicles that spend long hours in traffic or operate in warm climates.

Solid Alloy Housing for Reliable Heat Dissipation

Surrounding the circuit board is a solid alloy housing that works as both a mechanical structure and a heat sink. The body is machined with fins and grooves to increase surface area, allowing the heat captured by the aluminum board to diffuse into the surrounding air. The alloy shell also provides good resistance to corrosion and temperature cycling, so the bulbs stay looking clean and professional even after years of exposure to road spray, dust and under-hood heat. The robust structure helps the lamp hold its shape under vibration and makes installation and removal easier for technicians.

Constant Current Driver with Wide Voltage Range

Inside the base is a compact driver using an intelligent constant current IC. It is designed to work across 9–18 V DC so it can handle common voltage fluctuation in automotive electrical systems. The current is controlled around 0.56 A at 12 V, which keeps brightness stable and avoids the flicker seen in simple resistor based bulbs. The driver is also engineered to reduce digital and VHF radio interference, helping to protect in-car audio and communication systems from noise when the lamps are operating.

Precision Glass Lens for Stronger Penetration

At the front of the bulb a high refractive glass lens shapes the light into an efficient beam. The lens gathers the output from the LED array and concentrates it toward the reflector or the road ahead, increasing the useful intensity without demanding more power from the electrical system. The material choice gives good clarity and scratch resistance, while the optical design improves penetration in low visibility conditions. The result is a signal light that remains easy to pick out in rain, fog or busy city traffic.

Multiple Base Options for Broad Vehicle Coverage

The 4U16 series is available in 1157, 3157 and 7443 bases, covering a wide range of passenger cars, SUVs and light commercial vehicles. This lets distributors and workshops stock one LED platform and serve several socket standards, simplifying inventory management. Each version keeps the same LED, driver and housing design so performance is consistent, regardless of base type. For end users, this means they can enjoy the same dual color switchback effect whether their vehicle uses a bayonet 1157 socket or a wedge type 3157 or 7443 socket.

Designed for Everyday Use and Professional Upgrades

Together, the high power 3030 LEDs, aluminum circuit board, alloy heat sink body, constant current driver and glass lens make the 4U16 series a practical upgrade over conventional halogen or basic LED signal bulbs. The bulbs are bright enough for daily driving yet compact and straightforward to install, making them suitable for DIY enthusiasts and professional installers alike. For wholesalers and fleet customers, the family of three bases with identical performance offers a simple way to standardize on a reliable switchback solution across different vehicle models.