Kawasaki KAF820 Mule PRO-FX Brake Bulb Size

The Kawasaki KAF820 Mule PRO-FX brake light requires a P21/5W bulb size for proper operation and visibility. Available data for the specified lighting component covers the range from 2016 to 2022.

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
2021-2022	P21/5W
2016-2019	P21/5W

Bulb Specifications

Description	Bulb Size
ECE standard (Europe & worldwide). Dual-filament signalling bulb with BAY15d bayonet base. 12V, 21W/5W.	P21/5W

Other Locations

Additional Notes

The P21/5W is the brake bulb type used across all listed model years of the Kawasaki KAF820 Mule PRO-FX, spanning 2016-2022.
The P21/5W is a dual-filament bulb, meaning it contains two separate filaments within a single glass envelope. The higher-output filament operates at 21 watts for the brake or turn signal function, while the lower-output filament operates at 5 watts for a secondary function such as a running or position light.
The P21/5W operates on a 12-volt electrical system, which is consistent with standard automotive and utility vehicle electrical architecture.
This bulb type is governed by ECE (Economic Commission for Europe) standards, a regulatory framework recognized across Europe and many other markets worldwide.
The P21/5W uses a BAY15d bayonet base. The BAY15d designation indicates an offset dual-contact base, where the two pins are positioned at different heights along the base. This offset is a deliberate design feature that prevents the bulb from being inserted in the wrong orientation, ensuring each filament connects to its correct circuit.
Because the BAY15d base uses offset pins, it is not interchangeable with the BA15d base, which has pins at equal heights. Substituting a BA15d bulb in a BAY15d socket would result in incorrect fitment or reversed filament function.