This is a model H-IEC-A from the Hampden Engineering Corporation
out of East Longmeadow, Massachusetts.
From Hampden website:
MODEL #H-IEC-A Stepper Motor Trainer The Hampden MODEL H-IEC-A
Stepper Motor Trainer provides complete instruction in the control
and operation of both unipolar and bipolar stepper motors and stepper
motor drives. Troubleshooting experience is provided via fault switches
mounted at the rear of the unit and test points accessible on the front
panel. The MODEL H-IEC-A is the intelligent drive circuit, contained in
the left side of the housing. The right side of the housing may contain
either the MODEL H-IEC-A1 Unipolar Stepper Motor or the MODEL H-IEC-A2
Bipolar Stepper Motor.