Customer service responded to my email. When i asked why a couple of my leads are always inverted despite using the kardia 6l in the correct orientation, I was dissapointed that the response was "sometime a couple inverted leads happen" no assurance of correct reads. It does affect readings by cardiologists when leads are inverted. It's a good concept but was a headache for my cardiologist. My doctor got frustrated and had me stop using it and told me to throw it in the garbage.