I am very satisfied with my EKGraph. Easy to use, see ECG while being saved to device. Then easily transfer ECG via App to smartphone. Note this model uses Bluetooth to send data to the smart phone app. It works great. Other (competitor) systems do not send data to your smartphone. Using USB cable the data can also be transferred to a computer. Benefits: Great interface. Works well. Connects to smartphone. Can see ECG while recording on the device, and later on phone or PC. Do not need to have the phone with you to record an ECG. No subscription needed. Save ECGs on device and transfer to phone or PC. No waiting period to see ECG ! GREAT customer support and quick reply to questions. Rechargeable battery - lasts for many days on a charge! Cons: A little more expensive than similar looking devices - but those are not as easy to use and do not have great smartphone app.