Alla Lighting 3157/3457 T25 Switchback LED Bulbs - 6000K White/Amber, 2-Pack, 28x2835 SMD

Alla Lighting T25 3157 switchback LED bulbs are dual-color wedge lamps that deliver bright 6000K white for daytime/parking lights and vivid amber for turn signals in a single 12V-compatible unit.

These T25/3157-style switchback LEDs are an aftermarket upgrade designed to replace dual-function parking/DRL and turn-signal bulbs. Each bulb packs 28 high-output 2835 SMD LEDs to produce clear xenon-white illumination for running lights and an intense amber flash when signaling. The kit includes two bulbs and is built to work with vehicles that use the 3157/3457/4057/4157 and similar wedge sockets, offering a plug-and-play visual improvement when matched with appropriate resistors or vehicle electronics.

How do these bulbs switch between white DRL and amber turn signal?

Switchback bulbs use two internal LED circuits: one set emits a steady 6000K white for parking or DRL, and a second set switches to amber when the turn signal circuit activates. The change is automatic and synchronized to the vehicle's signal wiring without rewiring when the original lamp uses a dual-filament socket.

• Dual-circuit 28 x 2835 SMD layout for both colors
• 6000K xenon-white output for parking/DRL
• Bright amber LEDs for turn signals
• Requires a 50W 6Ω load resistor in some vehicles to prevent hyper-flash

Will these fit my car's 3157, 3457 or 4057 sockets?

The bulbs are built to the T25 wedge form factor and list broad compatibility with many dual-filament wedge part numbers such as 3157, 3457, 4057, 4157 and numerous manufacturer variants. Check your owner's manual or remove the old bulb to verify it is a dual-function wedge type before ordering.

• Common fitment: 3157, 3457, 4057, 4157 and equivalent codes
• Physical size: approx. 0.71" diameter x 2.50" length
• Designed for sockets using one bulb for both DRL/parking and turn signal
• May need load resistors or CAN-bus adapters in modern vehicles

Do I need additional parts or special wiring to install them?

Installation is typically plug-and-play in vehicles that already use dual-filament wedge bulbs, but some cars detect lower current from LEDs and will hyper-flash or show bulb errors. In that case add a 50W 6Ω load resistor or a compatible CAN-bus adapter to restore proper flash rate and avoid dashboard warnings.

• Works on 12V–18V DC electrical systems
• Add a 50W 6Ω load resistor if hyper-flash or error occurs
• Standard socket wiring remains unchanged for most installs
• One-year limited warranty from Alla Lighting for defects

How bright and durable are these LED switchback bulbs?

Each bulb contains twenty-eight 2835 SMD LEDs arranged for both intensity and even beam pattern. They are engineered to deliver a very bright white for visibility during the day and a high-contrast amber for signaling, while operating within typical automotive voltage ranges.

• 28 high-power 2835 SMD LEDs per bulb for strong output
• Rated for 12V–18V operation suitable for most cars and trucks
• Constructed for consistent color and brightness over time
• Sold as a set of two bulbs with 1-year warranty

Who is this for: These switchback LED bulbs are intended for vehicle owners wanting a single-bulb solution to modernize front parking/DRL lights and turn signals without changing fixtures. They suit DIY installers, car enthusiasts upgrading to LED illumination, and owners of vehicles that accept 3157/3457/4057-style wedge lamps — provided any required load resistors or CAN-bus modules are added for compatibility with modern electrical systems.