Diamond Reo C120 License Plate Bulb Size

The Diamond Reo C120 license plate light requires a 198 bulb size for proper operation. Data for the bulb size covers the range from 1992 to 1998.

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 Type	Shop
1997-1998	198	Check Price
1992-1993	198	Check Price

Description	Type	Shop
ANSI standard (US & Canada). Miniature wedge bulb (T5). 12V, 2W.	198	Check Price

The 198 bulb is the sole bulb type specified for the Diamond Reo C120 license plate position across all listed model years.
The 198 bulb follows the ANSI standard recognized in both the United States and Canada, meaning it conforms to a defined set of electrical and physical requirements shared across North American markets.
It is classified as a T5 miniature wedge bulb. The T5 designation refers to a tubular glass envelope with a width of 5/8 inch, and the wedge base type means the bulb is held in its socket by the glass base itself rather than by a separate metal base.
The 198 bulb operates at 12 volts and draws 2 watts, placing it among the lower-wattage miniature bulbs used in automotive lighting applications.
The 1993 and 1992 model years share the 198 specification with the 1997-1998 model years, indicating consistent fitment across the listed production range of the C120.
The wedge base format of the 198 bulb is not interchangeable with bayonet or screw-base socket types, as each base style requires a physically distinct socket design.