Participants will complete a phone screen and then one laboratory session. After completing in-person screening assessments, eligible participants will complete additional questionnaires. Participants will then choose an e-liquid flavor to use for the rest of the session. Participants will then sample two e-liquids that vary in nicotine content from little or no nicotine to a moderate level of nicotine, and questionnaires evaluating the subjective effects of each one. Participants will then complete a preference assessment where they choose between the two e-liquids. Participants will be blind to the nicotine contents.