Elera Pulse Oximeter

I bought this after finding myself losing energy while resting on hot summer days but regaining it while being active. I had an idea that it might be that I wasn't getting enough oxygen, and I bought this to be able to get an indication if that might be the case. After a few days I was able to spot a clear trend of my blood oxygen being a few points lower while resting. By being able to monitor easily at my convenience, this device helped me to have enough information to have a good discussion with my doctor. The only downside I have observed is that mine consistently reads 2 - 3 points lower than the professional unit.