I ved purchased your stethoscope but despite the cost of it plus the postal expense and the custom charge for a total amount more than 50 euros, the product do not work.
Maybe the jack is not operating and the microfone wires are insulated in a very poor manner with just a black scotch.
Why you do not test the product?
Schiacciasassi1 about iStethoscope Pro, v1.04