Clinical Study Comparing 7 ENDS Products and 1 Combustible Cigarette Using 2 Delivery Methods.

Inclusion Criteria: 1. Male or female aged 18 to 60 years of age inclusive. 2. BMI between 18 to 35 kg / m2 inclusive. 3. Healthy based on medical history and screening assessments, in the opinion of the Investigator. 4. Current smoker of at least 8 cigarettes per day on average. 5. Has been smoking for at least 12 months prior to screening. Brief periods of non-smoking (e.g., up to \~7 consecutive days due to illness, trying to quit, participation in a study where smoking was prohibited) are permitted at the discretion of the Investigator. 6. Able to participate, and willing to give written informed consent and comply with study restrictions. Exclusion Criteria: 1. Clinically relevant medical or psychiatric disorder, in the opinion of the Investigator. 2. Clinically significant abnormality on screening ECG. 3. Sustained blood pressure recordings at screening of \< 90 mmHg or \> 150 mmHg for systolic blood pressure, or \< 50 mmHg or \> 90 mmHg for diastolic blood pressure. 4. Sustained resting heart rate of \> 100 or \< 40 beats per minute at screening. 5. Positive result for urine drugs of abuse test or alcohol breath test at screening. If a positive urine drug test is observed, and it is believed the positive urine test is due to prescription drugs, the PI should obtain documentation that a) confirms the subject's use of the prescribed medication, and b) the prescribed medication will cause a false positive drug test. 6. Clinically significant abnormality in laboratory test results at screening, in the opinion of the Investigator. 7. Exposure to an investigational drug in a clinical trial within 1 month prior toAssessment Day 1. 8. Blood or plasma donation of \> 500 mL within 1 month prior to Assessment Day 1. 9. Positive urine pregnancy test at screening or Assessment Day 1 in female subject. 10. Any clinically significant concomitant disease or condition that could interfere with, or for which the treatment of might interfere with, the conduct of the study, or that would, in the opinion of the investigator, pose an unacceptable risk to the subject in this study.