Compared readings with another cuff style bp machine, an arm style automatic Machine and having my bp taken manually. This machine was consistently20 to 30 mmhg lower than anything else. Not a good thing if you’re taking measurements for bp meds. Example - bp taken manually was 148/89. Bp taken with this was 118/62. And while I wish the second number was true, if I took my bp meds based on this, I would never take my meds - and that would be bad. Maybe the thing’s defective -but I don’t think so..