https://www.ebay.ch/itm/293141158219

Good to know how a 3 lead cable looks like:

But take care, it only fits to the Heal Force Prince 180B Button Type ECG Monitor. For every device it s own special connector.

But there is a controversy about the definition of leads.

Scott Harden, PhD. MD. , developer of the Sound Card ECG says, his device is technically a single lead three electrodes device:

So, what is true now?

Scotts cable is build the same as the ECG cable sold on ebay. We are confused.