Agree with ProfessorDaffy... never know what you'll get. Someone asked me once "Okay, so my e-cig stopped making vapor after about 20 minutes.... what do I do now????" Then they explained that they had put no juice or prefilled carts on it... and it had been producing vapor for 20 minutes.... I just explained how to refill it... didn't know what flavor, strength they had been vaping ... and was honestly kind of shocked it lasted so long?!