I’d be VERY careful with those. There are cheap Chinese “smart watches” that simply show fake values for SpO2. People have put them on bananas and the watch sti

I’d be VERY careful with those. There are cheap Chinese “smart watches” that simply show fake values for SpO2. People have put them on bananas and the watch still “took a reading” and showed oxygen saturation to be “95-100%”. With these watches, the LEDs at the bottom flicker, but there’s no sensor to take an actual reading.