customizing the amount is easy, with reusable esticks. re reusable and feature various batteries. >> i can customize the amount of draw. if it's a colder or warmer hit. and that's just one piece of the puzzle. there's hundreds and hundreds of variations that you can make. >> in the e-cigarette cannister it can contain concentrations of nicotine from 0 to 25 or 26 milligrams, and juices giving it fruity flavour. here is where the controversy lies. critics are concerned that the attractive fruity flavours can help young people transition into conventional cigarettes. >> there's over 100 flavours, and we are the yoga land of e-cigarettes. >> reporter: it smells like pizza. i would ate this. for me, because of my background that's a concern. now is there a top limit, the concentration that you can put in in? >> now, there's not. you have the choice to buy own. >> reporter: we tend to regulate that. shine. >> correct. >> reporter: this is something in. >> they'll regulate. and we are prepared for that. >> reporter: but to far the f.d.a. has not

customizing the amount is easy, with reusable esticks. eusable and feature various batteries. >> i can customize the amount of draw. if it's a colder or warmer hit. and that's just one piece of the puzzle. there's hundreds and hundreds of variations that you can make. >> in the e-cigarette cannister it can contain concentrations of nicotine from 0 to 25 or 26 milligrams, and juices giving it fruity flavour. here is where the controversy lies. critics are concerned that the attractive fruity flavours can help young people transition into conventional cigarettes. >> there's over 100 flavours, and we are the yoga land of e-cigarettes. >> reporter: it smells like pizza. i would ate this. for me, because of my background that's a concern. now is there a top limit, the concentration that you can put in in? >> now, there's not. you have the choice to buy own. >> reporter: we tend to regulate that. shine. >> correct. >> reporter: this is something in. >> they'll regulate. and we are prepared for that. >> reporter: but to far the f.d.a. has not set