The smart display is honestly pretty hard to understand nut I'm pretty sure the percentage is the battery and the semi-circle of dashes is the amount of juice left. Anyways, this is fire. I got the frozen watermelon and it tastes really good, smells pretty good, and hits are smooth and provide that satisfaction of the mouth hit. There is adjustable flow but idk how any of that works so i usually keep it on low cuz i like how the smoke is. I've been using it about two weeks and it has gone down one juice bar, i have charged it maybe 5-10 minutes in those two weeks and after almost constant hits the battery has only gone down to 40%. It has leaked once within the first 4ish days but i have not noticed any other times. Would definitely purchase again and recommend to friends!