I purchased the device several months ago and it worked fine for a while. One day both of my computers stopped recognizing the EKgraph. Like most things in this throw away era I just tossed it in a drawer and forgot about it thinking for a hundred bucks it lasted long enough as most things last for a hundred bucks. About 2 weeks ago I got an email from Sono's cust service dept asking if I was satisfied with my purchase. After explaining what happened and a couple emails to diagnose my problem, I was completely surprised to receive a brand new unit yesterday! This company is very responsive. If you have afib (as I do) or other heart problems, this product is worth every penny and then some for your peace of mind! I showed it to my cardiologist and she is now suggesting it to her other patients.