Harley-Davidson FLHTKL Ultra Limited Low Tail Light Bulb Size

Harley-Davidson FLHTKL Ultra Limited Low tail light uses a 3157 bulb size for replacement applications. The chart covers 2015 to 2019 model 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
2015-2019	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 bulb is the tail light fitment for the Harley-Davidson FLHTKL Ultra Limited Low across the 2015-2019 model years.
The 3157 is a dual-filament bulb, meaning it serves two lighting functions within a single housing, typically handling both running light and brake light duties through separate filaments rated at 7W and 27W respectively.
The bulb operates on a 12V electrical system, which is standard for automotive and motorcycle applications in this class of vehicle.
The 3157 follows the ANSI standardization recognized in both the United States and Canada, placing it within a regulated specification framework for bulb geometry and electrical performance.
The T25 wedge base designation refers to the bulb's base type, which uses a plastic wedge rather than a metal bayonet or screw fitting to secure the bulb within its socket.
The dual-filament design of the 3157 means that a single-filament substitute, such as a 3156, would not replicate both lighting functions and is not a direct replacement despite sharing a similar base profile.