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 Headlight1973 – 1974 H6024
Back Up Light1973 – 1974 1156
Brake1973 – 1974 1156
Dome Light1973 – 1974 DE3423
Front Side Marker1973 – 1974 T4W
Front Turn Signal1973 – 1974 1156
License Plate1973 – 1974 12821
Parking Light1973 – 1974 12929
Rear Side Marker1973 – 1974 T4W
Rear Turn Signal1973 – 1974 1156
Tail Light1973 – 1974 12821
Courtesy1973 – 1974 DE3175