Symptomatic Relief of Action Tremor With Cala Trio Using Trio+ Bands

Inclusion Criteria: * Must be ≥22 years of age * Competent and willing to provide written, informed consent to participate in the study * Willing to comply with study protocol requirements For subjects with Essential Tremor: * A diagnosis of essential tremor * A tremor severity score of 2 or above in the dominant hand/arm as measured by one of the TETRAS upper limb postural tremor items * No significant alcohol intake within 8 hours prior to study visits For subjects with Parkinson's Disease: * Dominant hand/arm exhibiting postural tremor ≥ 2 (while in the off state) as assessed by the MDS-UPDRS postural tremor score * Stable dose of Parkinson's disease medications, if applicable, for 30 days prior to study entry Exclusion Criteria: * Implanted electrical medical device, such as a pacemaker, defibrillator, or deep brain stimulator * Suspected or diagnosed epilepsy or other seizure disorder * Any skin condition at the stimulation site that in the investigator's opinion should preclude participation in this study * Diagnosed with peripheral neuropathy affecting the tested upper extremity * Presence of any other neurodegenerative disease other than essential tremor or Parkinson's Disease * Subjects unable to communicate with the investigator and staff * Any health condition or concomitant medication that in the investigator's opinion should preclude participation in this study * Pregnancy or anticipated pregnancy during the course of the study * Botulinum toxin injection for hand tremor within 6 months prior to study enrollment * Are participating or have participated in another interventional clinical trial in the last 30 days which may confound the results of this study, unless approved by the Sponsor