This internal regulator is compatible with units that have only two connecting wires, plus earth, and fits all Beetles and 1600cc T2s from 1974 onwards. The part is also used with alternator conversion kits.
Voltage Reg, 14v 55/70amp, Internal, changed through the top access panel on some alternators.
T1 / Beetle 74-79
Karmann Ghia 74
T2 / Baywindow 74-79