I have been a medical professional for many years in the past. I know how to take pressure. I have had an Omron self BP cuff for about 7 years and it just got tuckered out and not doing its job any more so I decided to try a wrist model since I have trouble with my right hand and it is hard to pump the bulb to get the blood pressure.This thing did not work for me at all, I must have gotten a bad one. At first it was giving me a wonderful reading of about 140/72, I wish, I normally can't get below 150/80, I was 158/88 last week at the Doctors office.This morning when pressure is usually high this machine registered 63/44I am dead and don't know it yet. If you buy this make sure you can take it back, I bought it at a local CVS drug store, it cost more but now I don't have to waste time and money on shipping it back. Make sure you can test it first. I am going back to the manual unit. This is not a product you want to fool with, it literally can mean your life.