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Complete with device - shoelace and manual. The quality of the workmanship is good, the screen is bright. Powered by 2 AAA batteries (battery does NOT work). Displays saturation (SpO2), pulse (PR), and perfusion index (PI). It is possible to track readings in a mobile app. The button rotates the image on the screen. It is very simple to use: you need to put your finger under the sensors and press the switch on. Real-time data will be displayed on the screen. If there is no pulse or the perfusion index is low, the device is switched off immediately. pulse and saturation readings are close to readings of other devices (shoulder tonometer, smart bracelet, other pulsoximeter).
Very nice prize from Banggood won in the Money Game. Came in just 2 weeks through EU Priority Line. Works with 2 AAA batteries, has English instructions. I didn't install the app, I didn't see any reason to do it. Readings seem to be accurate enough, at least for me. I don't have anything to compare them to, but I see no reason to doubt them. Many thanks to Banggod for this gift!