This oximeter (PULOX mark) gives me satisfaction. It seems well built and well presented. In practice I noticed that it takes about a half minute to avoitr a stable indication. The curve that grows continuously heartbeat is quite fun to watch, even if it is not used much. Allow it to see an extrasystole (if accompanied by a lack of pulsation)? By cons I doubt this unit to draw a record over a long period. The machine holds the fingertip as would a clothespin. How to keep the finger for example during sleep? In this case, it is necessary to acquire a system in which the probe is separated from the screen. I do not use the software, otherwise very rustic design.