Great little product that'll help in regards to allowing me to puff of my JUUL in places you might need to keep your smoke discrete. As long as you keep a good seal around the mouthpiece when exhaling, nothing but plain air comes out the back. Great for when in the car, or in other locations you can't have a big cloud produced (you can use your imagination). Will def. recommend this to others if asked about it. The other thing I like about it is that it's small & portable, and has a slot on the top for my JUUL.
However, the one thing you might want to keep in mind is that a bit of force is required in your exhale to get the smoke "filtered" through the SLEAV. You need to keep this in mind, and also be mindful that if you have any residual smoke that you haven't cleared out from your lungs or is left in the mouthpiece, it will come out, so you want to get as much out through the SLEAV before you remove the mouthpiece from your mouth. A tip I have is to take smaller puffs from your JUUL, as emptying your lungs at a reduced speed could create a sort of choke/burning sensation on your lungs/throat from not being able to expel the smoke from your body fast enough. Overall, I give this device a A- for the required time/pressure to filter the air through the SLEAV to empty your lungs, but besides that minor quirk - it's a stellar device. It's also better priced than most alternatives on the market, and also has a higher puff/use count than others.