Conclusion: Wellue have an issue with their marketing and it's not as responsible as they claim to be (4 secs vs the industry 10 sec), and for the cost they are charging the public.
_______________________
Using Wim Hof Method Guided Breathing as a way to test my body's SPO2 level while breathing and holding the breath: [ Ссылка ]
Video recordings and live SPO2 readings:
Part 1: [ Ссылка ]
Part 2: [ Ссылка ]
Part 3: [ Ссылка ]
Part 4 (Summary): [ Ссылка ]
