 Methods and Design. This experimental protocol has been designed with the main aim to investigate the role of Tobacco Free Cigarettes TFC, also called e-cigarettes, in helping smokers to improve their lung health and to quit or reduce tobacco consuming. In particular, the investigators aim at investigating clinical physical symptoms, with particular focus on breathing quality and difficulties, the behavioral number of tobacco cigarettes smoked, and psychological wellbeing, mood and quality of life effects of shifting to TFC. 