Evaluating Selected Constituents in the Exhaled Breath Samples

Inclusion Criteria: 1. Be a healthy male or female aged 21 - 65 years, inclusive, at the time of signing the informed consent. 2. Be informed of the nature of the study, agree to and are able to read, review, and sign the informed consent document prior to any study procedures. The informed consent document will only be available in English. Therefore, the volunteer must have the ability to read and communicate in English in order to participate in the study. 3. Complete the screening process up to 28 days prior to Day 1. 4. Satisfy the user definitions of either cigarette user or ENDS/closed system user. 5. Agree to abide by the study restrictions. 6. Agree to abstain from use of alcohol 12 hours before the start of Day 1 for Groups I through VI. 7. Agree to abstain from use of any nicotine products 12 hours before the start of study day 1 for Groups I through VI. 8. Agree to not consume any mint or menthol flavor products (e.g., chewing gum, mouth wash, toothpaste, etc.) 12 hours before the start of testing for Groups I through VI. 9. Have a positive urine cotinine result at screening of \>200 ng/ml. 10. A female subject of childbearing potential must have been using one (1) of the following forms of contraception and agree to continue using it through completion of the trial: * hormonal (e.g., oral, vaginal ring, transdermal patch, implant, or injection) consistently for at least 3 months prior to Day 1; * double barrier method (e.g., condom with spermicide, diaphragm with spermicide) at screening. * intrauterine device for at least 3 months prior to Day 1; * a partner who has been vasectomized for at least 6 months prior to Day 1; * abstinence beginning at least 6 months prior to screening. 11. A female subject of non childbearing potential must have undergone one of the following sterilization procedures at least 6 months prior to Day 1: * hysteroscopic sterilization; * bilateral tubal ligation or bilateral salpingectomy; * hysterectomy; * bilateral oophorectomy; * Or be postmenopausal with amenorrhea for at least 1 year prior to Day 1. 12. Be judged by the Investigator to be in good general health as documented by the medical history, physical examination (including but may not be limited to an evaluation of the cardiovascular, gastrointestinal, respiratory and central nervous systems), vital sign assessments and by general observations. Any abnormalities or deviations outside the normal ranges for any clinical testing (e.g. vital signs) can be repeated at the discretion of the Investigator and judged to be not clinically significant for study participation. Exclusion Criteria: 1. Report receiving any investigational product, participated in any previous clinical study for an investigational drug, device, biologic, or tobacco product within 30 days prior to screening. 2. Report at screening using both ENDS and conventional cigarettes (menthol or non-menthol) (dual users), or use of other inhaled products (such as, but not limited to cannabis) in the past 3 months. 3. For ENDS users, be unable to perform CPS or incapable of drawing down the pod weight by 20-60mg after 3 attempts at screening. 4. If female, be pregnant, have a positive urine pregnancy test at screening, be lactating, breast feeding, or intend to become pregnant during the time period from screening through the end of the study. 5. Have any clinically significant results from physical examinations and vital signs assessments, as judged by the Investigator. 6. Have a systolic blood pressure \< 90 mmHg or \> 150 mmHg, diastolic blood pressure \< 40 mmHg or \> 95 mmHg, or heart rate \< 40 bpm or \> 99 bpm at screening. 7. Report a clinically significant illness during the 30 days prior to enrollment, as determined by the Investigator. 8. Report a history of drug or alcohol addiction or abuse within the past 1 year. 9. Have a positive screen for alcohol or drugs of abuse at screening or at check-in on Day 1. 10. Have a body mass index (BMI) greater than 40 kg/m2 or less than 18 kg/m2 at screening. 11. Have used prescription anti-diabetic medication and/or insulin therapy within 12 months of screening. 12. Have taken medication for depression, asthma, or chronic obstructive pulmonary disease within 6 months of screening. 13. Have used prescription or over-the-counter bronchodilator medication (e.g., inhaled or oral β-agonists) within 6 months of screening. 14. Be breast-feeding or pregnant female subjects (confirmed by a positive pregnancy test). Female subjects, who are considered women of child bearing potential (WOCBP) and sexually active, must be willing and able to use an acceptable method of contraception from screening through the end of the study. 15. Have experienced an allergic reaction following previous e-cigarette use or with exposure to any primary components of the e-liquids (nicotine, flavor, benzoic acid, propylene glycol, and/or glycerol. 16. Be or have a first-degree relative (i.e. parent, sibling or child) who is a current employee of CRO, Sponsor, or site. 17. In the opinion of an Investigator, be deemed not eligible to participate in this study.