Inclusion Criteria:  Adults ≥ 19 years of age (minimum 30% male/female)  Wrist circumference between 13.5 cm. - 23 cm. (5.3 in. - 9.1 in.):  At least 20% of total participants, greater than 20.6 cm. At least 20% of total participants, between 18.3 cm. & 20.6 cm. At least 20% of total participants, between 15.9 cm. & 18.3 cm. At least 20% of total participants, less than 15.9 cm. At least 10% of total participants, greater than 21.8 cm. At least 10% of total participants, less than 14.7 cm. Willing to volunteer to participate and to sign the study specific informed consent form  Exclusion Criteria:  Wrist circumference less than 13.5 cm. (5.3 in.) or greater than 23 cm. (9.1 in) Hand or body tremors Irregular heart rhythm (bigeminy, trigeminy, isolated ventricular premature beat (VPB), atrial fibrillation) Korotkoff sound K5 not audible Pregnant A musculoskeletal disorder that prevents a non-invasive device to be inflated/deflated on the arm Unwilling to volunteer to participate and to sign the study specific informed consent form