This is an emulator for the German Model 3 and 4 Enigma Machines. For the Model 3 use Null as the leftmost rotor and I through V for the rotors to the right. The rightmost rotor in considered to be the first rotor in the sequence. Use the B and C reflectors for M3. For the M4 machine, use I through VIII for the right most rotors, Beta or Gamma for the leftmost and use the 'thin' reflectors.

A web page with many links about the Enigma