Does Abstinence From E-cigarettes Produce Withdrawal Symptoms?

Inclusion Criteria: * 18 years or older * Able to read and understand verbal English fluently * US citizen or resident alien * Primarily uses e-cigarette product types of refillable tanks or modified devices * Uses nicotine-containing e-liquid * Has baseline urinary cotinine concentration of \> 100 ng/ml * Has used e-cigarettes daily for the last 2 months * Has a home or cell phone * Agrees to abstain from tobacco, marijuana and other illegal drugs during study Exclusion Criteria: * Smoked \> 5 tobacco cigarettes in the last month * Used non-cigarette nicotine, tobacco or quit smoking products on \>5 days in the past month * Use of cannabis (either marijuana or synthetic cannabis) \> 5 times in the past month or positive test for cannabis use at screening * Current (last 6 months) Generalized Anxiety Disorder, Major Depressive Disorder, Attention Deficit Hyperactivity Disorder or moderate/severe Substance Abuse Disorder * Multiple legal, social health, work or school problems in the past month due to alcohol or drug use * Pregnant or breastfeeding * Previously a participant in the current study * Use of prescribed or non-prescribed psychoactive medication \> 5 times in the past month * Expired carbon monoxide level \> 8ppm