When doing replacement or upgrading on 1973 – 1974 Volkswagen Thing, the bulb size guide is necessary for you to take the reference.
Jump to corresponding car model with the catalog bellow.

High Beam and Low Beam Headlight 1973 – 1974 H6024
Back Up Light 1973 – 1974 1156
Brake 1973 – 1974 1156
Dome Light 1973 – 1974 DE3423
Front Side Marker 1973 – 1974 T4W
Front Turn Signal 1973 – 1974 1156
License Plate 1973 – 1974 12821
Parking Light 1973 – 1974 12929
Rear Side Marker 1973 – 1974 T4W
Rear Turn Signal 1973 – 1974 1156
Tail Light 1973 – 1974 12821
Courtesy 1973 – 1974 DE3175