Kubota RTV900XT Turn Signal Bulb Size

The Kubota RTV900XT rear turn signal bulb uses a P21/5W size. The replacement chart covers 2015 to 2016 vehicle production 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.

Rear Turn Signal

Years	Bulb Size
2015-2016	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 specified rear turn signal bulb for the Kubota RTV900XT across the 2015-2016 model years.
The P21/5W is an ECE-standard dual-filament bulb, meaning it contains two separate filaments within a single glass envelope, each rated at a different wattage.
The bulb operates on a 12V electrical system, with the two filaments rated at 21W and 5W respectively. The higher-wattage filament typically serves the turn signal or brake function, while the lower-wattage filament serves a secondary role such as a running or position light.
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 to prevent incorrect installation of the bulb.
The ECE designation on the P21/5W indicates the bulb conforms to the Economic Commission for Europe regulatory standard, which is widely adopted across European and international vehicle markets.
Because the BAY15d base is offset, it is not interchangeable with the BA15d base, which shares a similar physical form but features pins at equal heights. Substituting one for the other is not possible without modification.