International S120 front side marker bulb size 194 and rear side marker bulb size 97 represent the specifications for this truck model. The replacement chart covers 1956 to 1957 production years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The International S120 uses two distinct bulb types across its side marker positions: the 194 for front side markers and the 97 for rear side markers, both covering the 1956-1957 model years under the Light Duty classification.
The 194 is an ANSI-standardized miniature wedge bulb in the T10 form factor, rated at 12 volts and 3.78 watts. The T10 designation refers to a tubular bulb body roughly 10/8 of an inch wide, with a wedge-style base that requires no separate socket retainer.
The 97 is an ANSI-standardized single-filament bulb with a BA15s bayonet base, rated at 12 volts and 13 watts. The BA15s designation indicates a single-contact bayonet fitting with a 15mm base width.
The 97 is noted as a variant of the 1156 bulb type. While the two share a BA15s bayonet base, they are not identical, and substituting one for the other without confirming wattage and pin offset compatibility may result in incorrect fitment or electrical mismatch.
The wattage difference between the two bulbs is substantial. At 13 watts, the rear 97 bulb draws considerably more power than the 3.78-watt front 194, reflecting the typically higher visibility demands placed on rear marker lighting.
Both bulb types conform to ANSI standards applicable in the United States and Canada, indicating standardized dimensional and electrical tolerances across manufacturers producing these part numbers.
The wedge base of the 194 bulb is not interchangeable with the BA15s bayonet base of the 97. The two bulbs require different socket types, and the front and rear marker housings on the International S120 are therefore not cross-compatible for bulb replacement purposes.