Colyn,

I have the Checkmate unit, and it appears to work fine, though I don’t have any way to judge if it’s accurate (what is my blood oxygen saturation percentage?) All I know is I get a heart rate and O2 % reading, usually without having to reposition it on my finger too much. The II version looks cool, as the mass of the current unit on the end of your finger is noticable, and to read it you have to point  your finger back toward you.

 

Paul Bricker

N63PB