This is a multi-center, prospective, non-randomized study to evaluate the performance of the study watch PPG algorithm in detecting irregular rhythms suggestive of atrial fibrillation (AF) in subjects at risk of having an event of AF in the free living (home) environment.

Inclusion Criteria:

• At least 22 years old
• Able to read and speak English
• Able and willing to sign written Informed Consent
• Interest in participating in the study
• At risk of having an AF event, as determined by having a diagnosis of paroxysmal AF (PAF) and meeting one of the following: (a) scheduled or to be scheduled to undergo AF ablation, (b) with implantable loop recorder (ILR), implantable cardioverter defibrillator (ICD), permanent pacemaker (PPM), holter monitor, or adhesive monitoring patch with documented AF burden of ≥25% in the 3 months prior to consent date, (c) CHA2DS2VASc ≥3, (d) Left atrial diameter ≥4.4 cm
• Without significant limitation in ability to participate in the study, in the opinion of the investigator

Exclusion Criteria:

• Currently in a paced rhythm
• Currently on class Ic or class III antiarrhythmic medication that has been successful in eliminating AF (no documented AF of more than 30 seconds since the initiation of the medication)
• Had successful AF ablation (no documented AF of more than 30 seconds post procedure)
• Known severe allergy to nickel or metal jewelry
• Known allergic reaction to adhesives or hydrogels or with family history of adhesive skin allergies
• Are diagnosed with persistent AF
• Use of implantable neuro-stimulator
• Open injury or rash where the study device or comparator will be worn

At risk of having an AF event, as determined by having a diagnosis of paroxysmal AF (PAF)