actually this is the yellow. The crappy iphone pic fools you how long should a piece of clay last (average number of uses)
For me its hard to tell because it really depends on how bad the car is contaminated to begin with, if I had to guess or put a specific use range I would have to say 3 cars for a full bar...
Those are the boxes for blue though. For Riccardo, I usually get about 2-3 cars per half bar of clay with average contamination.