Good, not quite perfect.
Works good, but only if you get it placed perfectly. This is a good item, and priced well. It was not off by much, we tested it with a real medical arm wrap model. My cousin is a nurse, and she was the one who tested it. After three slight movements on the wrist, it was only around 3 to 5 psi higher or lower. It does well considering. You also need to sit correctly when using it. (Described in the Manual) For casual use it is fine. However if you are very much in need of daily accurate test's, you may want to consider a higher end arm mount.
Rating: 4 stars