Kardia Band attaches to the Apple Watch like any other replaceable watch band. The user rests a finger on the sensor pad embedded in the band, allowing an EKG reading to be taken. The Kardia Band transmits its EKG reading to the Apple Watch (via a high-pitch audio signal) where it's displayed in real time as a moving waveform. When the 30-second EKG is finished, the user can view it on their phone or easily send the results as a PDF to their physician. Doctors can diagnose hundreds of diseases using EKG data, but AliveCor is cleared by the FDA only to record the EKG and to advise a user that the reading is normal, or possibly indicative of atrial fibrillation.