O2 = Oxygen my friend Have a great day🏁

02 is oxygen and usually in tanks and you have a nose canela.

1) Google search for What is O2
https://www.google.nl/search?q=what+is+O2

2) What is Oxygen (O2)? - Definition from Safeopedia
https://www.safeopedia.com › ... › Oxygen (O2)
https://www.safeopedia.com › ... › Oxygen (O2) -
30 Nov 2021 — Oxygen (O2) is a gas, an essential component of air, and a necessary element for the sustenance of all living things. It is colorless, odorless, ...

And also see:
3) Google search for: COPD SpO2
https://www.google.nl/search?q=copd+spo2

My daughter in law is on oxygen 24/7. Poor love her body is fighting against autoimmune disease. Her heart is good, but it has badly scarred her lungs. Life for some is cruel. Stay safe.