I have something similar in price but for my wrist and it is ballpark accurate (so up to about 5 off depending on many factors). But only when used as described

I have something similar in price but for my wrist and it is ballpark accurate (so up to about 5 off depending on many factors). But only when used as described on the correct wrist. Tested with my doctor and he showed the other wrist is highly inaccurate. Good enough for home testing but that is about it.