Harley-Davidson FLHTCUL Electra Glide Ultra Classic Low Brake Bulb Size

Harley-Davidson FLHTCUL Electra Glide Ultra Classic Low uses a 3157 bulb size for brake applications. The replacement chart covers 2015 to 2016 model years with corresponding bulb size specifications.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	US Type	EU Type	Shop
2015-2016	3157	P27/7W	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3157	Check Price

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Additional Notes

The 3157 is an ANSI-standardized bulb type recognized across the United States and Canada, operating at 12 volts with a dual-filament design rated at 27 watts for the brake/stop function and 7 watts for the tail/running function.
The T25 designation refers to the bulb's wedge-base form factor, a bayonet-style plastic wedge base that does not require a separate socket retainer to hold it in place.
The Harley-Davidson FLHTCUL Electra Glide Ultra Classic Low uses the 3157 bulb for the brake light position across the 2015-2016 model years.
The dual-filament construction of the 3157 allows a single bulb to serve two distinct brightness levels within one housing, with the lower 7W filament active during normal running conditions and the higher 27W filament activating under braking.
The 3157 shares its T25 wedge base with several related bulb types in the same family, such as the 3156 (single-filament) and the 4157, which means physical fitment alone does not confirm electrical compatibility across these variants.