I bought the SonoHealth unit and Alivecor Kardia unit. SonoHealth unit pros: SonoHealth unit cons: Relatively compact unit Three second switch. Self contained records. Unreliable sync Do not need start a phone Unreliable switch. app to use. Graph printout uses heavy lines Kardia pros Kardia cons Very compact Needs a phone app to record Detailed graph printout Need a membership to review display result App allows you to store other info - BP - Meds - Weight