Kubota RTV-X1120D Turn Signal Bulb Size

The Kubota RTV-X1120D rear turn signal uses a bulb size of P21/5W or P21W. The replacement chart covers vehicle production from 2015 to 2017.

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
2017	P21/5W
2015-2016	P21W

Description	Bulb Size
ECE standard (Europe & worldwide). Dual-filament signalling bulb with BAY15d bayonet base. 12V, 21W/5W.	P21/5W
ECE standard (Europe & worldwide). Single-filament signalling bulb with BA15s bayonet base. 12V, 21W.	P21W

The P21W bulb appears in the Kubota RTV-X1120D rear turn signal position for the 2015-2016 model years. It is an ECE-standard single-filament signalling bulb rated at 12V and 21W, fitted with a BA15s bayonet base.
The P21/5W bulb is specified for the 2017 model year rear turn signal position. Unlike the P21W, it carries a dual-filament design rated at 12V with a 21W/5W output split, and it uses a BAY15d bayonet base.
The BA15s base on the P21W and the BAY15d base on the P21/5W are not interchangeable. The BAY15d base features two offset locating pins to prevent incorrect installation of the dual-filament bulb, while the BA15s base uses a single-pin alignment. Substituting one for the other is not physically possible without modification.
The shift from a single-filament P21W to a dual-filament P21/5W between the 2016 and 2017 model years indicates a change in the rear lamp assembly design for the Kubota RTV-X1120D, as the two bulb types serve different circuit configurations.
Both the P21W and P21/5W conform to ECE regulations, a lighting standard recognized across Europe and numerous other markets worldwide. This classification governs the photometric and electrical performance requirements each bulb must meet.