All of the iHealth Blood Pressure Monitors have been tested under both U.S and the European standards for non-invasive blood pressure monitors, and received FDA approval (USA) as well as CE medical certification (Europe).
However, there are some physiological diversities (like: Ulnar and Radial artery location), within an individual's wrist, that can affect the blood pressure readings from person to person. For those concerned with accuracy across several users, we suggest using one of the bicep-style monitors, as they experience less volatility due to arterial location.