Question 1

Is the Checkme O2 Ultra more accurate than the O2 Max?

Accepted Answer

No. In my three-night test the O2 Max scored 90.7 against the Ultra’s 87.3, and held inside 2% of a hospital Nonin 3150 for 99.6% of the night versus the Ultra’s 99.0%. That said, both posted an identical +0.2% average bias, so neither one systematically reads high or low compared to the other.

Question 2

Are the Checkme O2 Max and O2 Ultra the same device?

Accepted Answer

No, though they share a great deal. Same parent company, same ViHealth app, same finger sensor, same export formats. The Ultra adds a bigger battery, a finer 1-second recording interval, slightly longer recordings and a magnetic charger; the O2 Max adds an FDA 510(k) clearance and scored higher on my bench.

Question 3

Does the Checkme O2 Ultra have FDA clearance?

Accepted Answer

I could not find one. The Checkme O2 Max is covered by Viatom’s 510(k) K191088, cleared 2 December 2019 for the “Checkme O2 Pulse Oximeter” under product code DQA; I found no equivalent clearance listing the O2 Ultra. If the clearance matters for your situation, that alone settles the choice.

Question 4

Which one is better for CPAP and OSCAR?

Accepted Answer

Either. Both export a clean CSV that imports into OSCAR without cleanup, which is the main thing CPAP users need. If anything the Ultra has the edge here, because it records at a 1-second interval against the O2 Max’s coarser one, so its CSV carries more detail per hour of sleep.

Question 5

How long does each battery actually last?

Accepted Answer

The O2 Max covers about three nights per charge at 72 hours. The Ultra’s manual rates it at 100 hours or more, and it stores four 12-hour recordings before you need to sync. Note that Wellue’s current product page lists the Ultra at 72 to 96 hours rather than 100+, so treat the exact ceiling as approximate; I never ran either device to a flat battery.

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