Hey there guys, i picked up 2 liberty v9 cartridges (that have been bought in bulk by an online business and had thier logo but on the box) and a 1300 mAh battery from the same company from a shop in town (im not sure if i can specify companies & brands) but long story short ive got 3 different types of "refillable syringe" Concentrates with all different thicknesses. I put the least viscous and least expensive in first and it worked fine I guess, so then I opened up the 2nd one and filled it with the most viscous and repeated the filling process. I hit the thick cartridge once or twice before it formed a HUGE bubble (i mean if i had taken that much in id have been on the moon) but i figured well maybe thats just the chamber filling slightly after reversing the air pressure (as ive read they sometimes do and also overfill and top leak) but after the next pull all it did was make the bubble bigger. I then did more research and found the "Hairdryer trick" and as the bubble worked its way to the top another started forming at the same hole right under the original one so i worked that one up too, so i finally took a rip, keep in mind that little bubbles come out of the other 3 holes after a pull, and those were the only bubbles I saw and i thought PROBLEM SOLVED. Until i looked at it again after a round of a game (15-25mins) and a bubble that connected horizontally had formed even though it was vertical the entire time and its about 1.5x bigger than the original bubble. The last thing i have to say is that i shone a very powerful flashlight in it and its not working its way up the tube and i stuck a needle to the bottem and its not even 2mm off the bottom of the central post and the material isnt burnt or taste burnt so im a bit lost. It doesnt help i stopped smoking in '12 and just started up again and it feels like a science lol. Im not sure what a "good" hit from a concentrate pen hit is (nail and dome type cloud? Idk) but i hold in smoke until there's none to very little from a good size water pipe so i dont know what this produces at 3.7v or 3.8v output but i hope i can get a high like that off a pen. Thanks for readin' and if you have any knowledge of this id really appreciate the gesture if you posted here please.