L9 ECG PPG Blood Pressure Oxygen Heart Rate Monitor Waterproof IP68 Smart Watch worth to buy? Thanks for it if those of you who have purchased L9 ECG PPG Blood Pressure Oxygen Heart Rate Monitor Waterproof IP68 Smart Watch could share about what you think of the product. I would love any extra info, as it is quite pricey as $59.96 and I just want to know it is good before paying for it.