This coil winding machine is a genuine and original winder created by an engineer who previously worked for a transformer manufacturing company. To manufacture transformers, coils are wound around bobbins dozens or hundreds of times, a task nearly impossible to do by hand. This winding machine allows for easy mass production. It was used to manufacture small step-up/step-down transformers for electronic circuit boards. The target cores were EI40, EE40, and EI28, but it can be adapted for others by changing the jigs. It operates on AC100V, using a household power outlet. Commercial models are very expensive, but this is offered at a low price, so please purchase only if you understand coil winding machines.