This is the number 57 bulb with a small / medium sized globe and a single filament in 12 Volt. This bulb fits all Pick Up Truck, Station Wagon, Sedan Delivery and Jeepster Speedometer and gauge clusters and also fits 1957-1986 round speedometers in the CJ3B, CJ5, CJ6, CJ7, CJ8, FC, DJ3A to illuminate the dash.
The bulb might also fit other applications but you will have to check per application.