RecruitingClinical trialDeveloping and Testing Health Warning Labels on the ENDS DeviceIn this project, after systematically developing electronic nicotine delivery systems (ENDS) pictorial health warning labels (HWLs), a proven clinical lab model will be used to examine and test their effect when these are placed on the ENDS device on a variety of subjective (e.g. satisfaction, harm perception, nicotine dependence, intention to quit) and objective outcomes (e.g. plasma nicotine, puff topography) in young adults.