FeaturesModern LED appearance with instant on and off.Compatible with GMC Sierra 2500/3500 front turn signal bulbs.Plug and play no modification with factory 3157 bulb size.Multiple brightness levels available.OverviewLED Indicators. The factory incandescent turn signals on your vehicle illuminate in a slow glow taking a moment to turn off and on. With replacement LED bulbs you can immediately update your vehicle with the instant on-off blinking of modern LEDs. This instant activation adds a modern and distinct look to your vehicle.Brightness. Your vehicle uses a 3157 dual-filament bulb. They light up with low power as parking lights then they get brighter when the turn signal or hazards are activated. Diode Dynamics bulbs are designed to match the factory brightness ratio so there is enough distinction between low and high brightness levels. As with all Diode Dynamics LED bulbs these turn signal bulbs are rated with accurate measured lumen figures not calculations or guesses.Switchback. These bulbs illuminate in a bright white for the low power setting for your running/parking light then switch to intense amber when the turn signals are activated. When the turn signal is switched off they return to the original white output. Please note: in order to properly see the white you must have clear reflectors/lenses over the turn signal bulb.Reduced Load. If you experience hyperblinking the most tried-and-true method to correct this is to add resistors (sold separately). Since a 6-ohm resistor uses about the same power as a standard turn signal bulb these can be used on any vehicle but does require tapping factory signals. One resistor is needed to replace each turn signal bulb.

• Molded construction with sturdy double terminals
• Direct replacement for your factory bulb
• Increased output with LED Appearance
• Plug and play simple installation

This Part Fits: