Camera very simple to use, it allows to analyze the loss of warm decor and realize if a piece is poorly insulated or not. The difference between the reference temperature and controls is adjustable on 3 pre-set positions. Just click once to take the reference temperature and then walk the "green flash" on the wall to see what "spoke" change color. Blue if it's cold and red if it is warmer than the reference temperature. Indispensable!