Harley-Davidson FLHTCUTG Tri Glide Ultra Tail Light Bulb Size

Harley-Davidson FLHTCUTG Tri Glide Ultra tail light uses a 3157 bulb size. The replacement chart covers 2011 to 2020 production years with corresponding bulb 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	Bulb Size
2011-2020	3157

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3157

Other Locations

Additional Notes

The 3157 is the tail light bulb size for the Harley-Davidson FLHTCUTG Tri Glide Ultra across the 2011-2020 model years.
The 3157 is a dual-filament bulb, meaning it contains two separate filaments within a single housing. One filament operates at 27W for braking or turn signal functions, while the other operates at 7W for running light functions.
The 3157 follows the T25 wedge base form factor, which refers to the tapered plastic base that secures the bulb directly into the socket without a separate metal base or bayonet pins.
The bulb operates on a 12V electrical system, consistent with standard automotive and powersports vehicle wiring.
The 3157 designation is an ANSI standard recognized in both the United States and Canada, placing it within a regulated classification system that defines its electrical and physical characteristics.
The 3157 shares its T25 wedge base with several related bulb types, such as the 3156 and 4157. However, the 3156 is a single-filament variant, making it non-interchangeable in applications that require dual-filament operation.