Before You Buy This 3157 switchback LED bulb uses an intelligent driver to seamlessly switch between two colors: amber/yellow for front turn signals (can't be used as taillights or rear turn signal lights) and white for daytime running lights. It’s specifically designed for factory-installed single bulbs that integrate dual functions—your vehicle’s original bulb must support dual-color functionality. Otherwise, the bulbs may only display one color or fail to light up properly. Note: Fits standard bases only; not compatible with CK-type sockets. 500% SUPER BRIGHT 3157 LED bulb specifications: Working voltage: DC 12V, current: 350 mA. Each bulb has a power of 4.2W—just 1/4 the energy consumption of stock bulbs—but delivers an impressive 2,000 lumens of brightness, 5X brighter than original halogens. This extreme brightness ensures your vehicle is quickly and clearly visible in rain, fog, or other harsh weather, enhancing overall driving safety. 98% VEHICLE COMPATIBILITY Yorkim 3157 turn signal bulbs feature a built-in IC driver module for hassle-free, plug-and-play installation—no wiring needed, no electromagnetic interference, suitable for most vehicles. A few special vehicles with unusual CAN bus systems or installation requirements may require a 50W 6Ω load resistor to prevent hyper-flashing or error codes. 50,000 HOURS LONG-LASTING DURABILITY Our 3157 bulb feature an aviation-grade aluminum housing that efficiently dissipates heat, protecting core components and extending lifespan to over 50,000 hours—no more frequent replacements. WORRY-FREE CUSTOMER SUPPORT Due to the diversity of automotive electrical systems, rare compatibility issues may occur in a small number of vehicles (e.g., missing colors, no illumination, or turn signal malfunctions). In most cases, adding a load resistor resolves these issues. Contact us via Amazon buyer messages for troubleshooting help or replacement solutions—we’re here to assist! WIDE FITMENT This 3156 LED bulb is easy to install with a non-polarity design (no need to worry about positive/negative orientation). Fits socket models: 3156, 3157, 3056, 3356, 3456, 4156, 3047, 3157A, 3057, 3155, 3157NA, 3357, 3457, 3457A, 4057, 4114, 4157, etc.