Disposable vape, just three components but what it bugs me how does it know when it's empty. Led flashes when no juice is left but how? What makes led flash? The Synthetic Nicotine Loophole Fueling a Return to Teenage Vaping The New York Times How do I get the rest of the oil out of this dead disposable vape pen? : r ILTrees Why My Disposable Vape Pen Died Before Empty? And Fix It!