Here's a partial list of models that are illustrated in the book:

• Model I

• Model VI

• Model VIII

• Model X

• Model XII

• Model  XV

• Model  XX

• Harko Senior

Some of the other units with no model #:

• Audion Detector

• RF Amplifier

• Two Step Audio Amplifier

• Condenso-Unit

• Detecto-Unit

Plus many other pieces, combo units and parts are shown and described.