Rad-67 Repeatability and Reproducibility

Inclusion Criteria: * At least 18 years of age * Weight at least 110 pounds * Subjects with the intention of being screened for eligibility to donate blood * The subject has given written informed consent to participate in the study Exclusion Criteria: * Subjects with skin abnormalities at the planned application sites that may interfere with sensor application, per directions-for-use (DFU) or trans-illumination of the site, such as burns, scar tissue, infections, abnormalities, etc. * Subjects unwilling to remove nail polish or acrylic nails * Subjects with blood cancers such as leukemia * Subjects with hemoglobin disorders such as sickle-cell anemia and thalassemia or with known history of infectious diseases such as HIV/AIDS, syphilis, hepatitis, etc. * Subjects with self-disclosed/known pregnancy at the time of enrollment * Subjects deemed not suitable for the study at the discretion of the investigator * Subjects unlikely to be able to refrain from excessive motion during data collection. Excessive motion includes postural changes, making hand gestures, involuntary muscular movements, etc.