oximeters of like this are quite cheap only. accuracy is so-so
even my own honor band got an oximeter, but its only going to run when activated, not all the time. and its not particularly accurate.
it uses is light shining thru the finger to detect the oxygen composition in your bloodstream but this kind of crocodile clip is not comfortable to use for long time. and probably dont have logging (only real-time)

i got my own CONTEC CMS50F with finger probe (its like a watch with wire to attach to the finger) that can track overnight because of sleep apnea paranoia that turned out to be false.
well guess can use for kobis if needed.

probably not
probably too much caffeine just faks up my sleep.
logger doesnt indicate any drop in SPO2 and after cutting more caffeine i have more well-rested nights than before.

i thought i was the only one lol
See price of overnight sleep test + need to take day off
vs see price of Honor Band 5 or some SPO2 meter with overnight log
end up take the Honor Band, still useful as HR tracker, SPO2 sensor only detect during time of activation only, no tracker + not really good accuracy.
since was still worried about OSA, end up bought that Contec SPO2 tracker anyway. in the end probably not OSA, probably just caffeine induced insomnia + very rowdy neighbour 🤣

less caffeine enough
earplugs on standby if awaken due to loud noise, can plug in straight