





Diode Dynamics 4257 HP24 LED Bulb - Cool - White Switchback (Single)
Give your front turn signals a modern, dual-color upgrade with the Diode Dynamics 4257 HP24 Cool White Switchback LED Bulb. It illuminates cool white when your headlights are on and flashes amber when you activate the turn signal, combining a clean running-light appearance with a distinct amber signal. Sold individually.
The HP24 uses sixteen amber LED chips and eight white LED chips, with high-power Samsung LEDs arranged around the bulb. Its 410-lumen output is measured in-house by Diode Dynamics, providing approximately double the total light output of the factory bulb. There is no yellow appearance when the bulb is switched off.
An aluminum casing helps dissipate heat, while constant-current circuitry and transient suppression support reliable operation. The custom-molded base features sturdy double terminals for a secure fit in the factory socket. The bulb is non-polar and CK compatible, with a simple plug-and-play bulb installation.
Some Ford vehicles use a dual filament 4257-size front turn signal bulb, which allows you to add "switchback" functionality to your turn signal location. From the factory, the front turn signal lights up half-power amber when the headlights are on, and flashes full-power amber when the turn signal is activated.
Included in the Box
- One (1) Diode Dynamics 4257 HP24 Cool White Switchback LED bulb
Fitment
The 4257 HP24 Switchback bulb features a custom-molded base connector, making it a true replacement for factory incandescent 4257-size front turn signal bulbs. Unlike a 3157 bulb that includes tabs on either side of the bulb, a 4257 bulb does not. The 4257 HP24 Switchback bulb is compatible with Ford vehicles using a dual-filament 4257-size front turn signal bulb with a clear reflector lens.
Confirm your vehicle’s original bulb size and lens configuration before ordering.

