The International B122 uses a 194 bulb size for front side marker applications and a 97 bulb size for rear side marker positions. The replacement chart covers 1959 to 1960 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.
The International B122 uses two distinct bulb types across its front and rear side marker positions for the 1959-1960 model years, with Light Duty trim applications covered by both.
The 194 bulb serves as the front side marker across both covered model years. It follows the ANSI standard recognized in the US and Canada and takes a T10 miniature wedge form factor operating at 12V and 3.78W.
The T10 wedge base of the 194 bulb is a tool-free, push-in fitment, which is a common trait of low-wattage parking and marker lamp applications in mid-20th century vehicles.
The rear side marker position on the International B122 uses the 97 bulb for the 1959-1960 model years. It is also an ANSI-standard bulb recognized in the US and Canada, rated at 12V and 13W.
The 97 bulb uses a BA15s single-contact bayonet base, a twist-lock style mount that differs fundamentally from the wedge base of the 194, meaning the two bulb types are not interchangeable between front and rear positions.
At 13W, the 97 bulb draws considerably more power than the 3.78W 194 bulb, reflecting the higher luminous output typically required of rear marker lamps compared to front ones.
The 97 bulb is described as a variant of the 1156. While both share the BA15s bayonet base, the 97 operates at a lower wattage than the standard 1156, and substituting one for the other without confirming socket and circuit compatibility carries a risk of mismatched output or load.
Both the 194 and 97 bulbs are single-filament designs, meaning neither supports dual-intensity functions such as combined running and brake light operation.