Inclusion Criteria:
* Male and female cigarette smokers who are between 21 and 65 years of age.
* Self-report having vaped at least once in the last six months (i.e. tried vaping) or are currently vaping.
* Self-report smoking at least 5 filtered cigarettes per week for at least the last 12 months.
* Not currently undergoing smoking cessation treatment or planning to quit prior to enrollment in the study.
* Able to attend 3 in-person visits in the Philadelphia area.
* Willing to smoke a cigarette in a ventilated smoking laboratory at each in-person visit.
* Capable of giving informed consent, which includes compliance with the requirements and restrictions listed in the combined consent and HIPAA form.
* Able to communicate fluently in English (i.e., speaking, writing, and reading).
Exclusion Criteria:
Smoking Behavior
-Use of any nicotine containing products other than cigarettes or ENDS. Participants reporting isolated use of other nicotine containing products less than 5 times per month are eligible to participate.
Alcohol and Drug Use
* History of substance abuse (other than nicotine) in the past 12 months and/or currently receiving medical treatment for substance abuse. Attendance at alcoholics anonymous or narcotics anonymous meetings will not be considered medical treatment for the purposes of this protocol.
* Current alcohol consumption that exceeds 25 standard drinks/week.
Medical
* Women, including all individuals assigned as female at birth, who are pregnant, breast feeding, or planning a pregnancy over the duration of the study period.
* Any psychiatric disorder that (as determined by the Principal Investigator) would interfere with study participation
* Serious or unstable medical condition. Applicable conditions will be evaluated on a case-by-case basis by the Principal Investigator.
General Exclusion
* Past, current, anticipated, or pending enrollment in another research program over the study period that could potentially impact participant safety, study data, and/or the study design as determined by the Principal Investigator.
* Any circumstance, medical condition, illness, disorder, adverse event (AE), or medication that could compromise participant safety or significantly impact study performance as determined by the Principal Investigator. Participants may be withdrawn for any of the aforementioned reasons at any point throughout the study.
* Significant non-compliance with the protocol and/or study design as determined by the Principal Investigator. Participants may be withdrawn at any point throughout the study.
