The tolerances have been reformed, and there are no longer different O ring options. The fitment is fairly tight, but most don't have any problems removing the top caps or the carto when the need to. These tanks do not leak unless the carto is flooded, then you may get some leaking out of the battery connection on the carto, but this goes for any carto tank. If you follow the instructions on filling properly you should never get leaks. Also when punching the carto, be careful not to punch through the center airtube, this will help alleviate carto flooding issues. You will find these are the easiest tanks to fill once you get the hang of it. It takes me about 10 seconds to remove the cap, fill and replace the cap.
Here is some more info: The Lava Tank Maintenance Thread : Lavacorps - International Vapers Club
And more: Sumerdawn's Review Thread : Lavacorps - International Vapers Club
These tanks will accept Boge, Smoktech, and Kanger 35 mm standard length stainless steel cartos, or any other brand of this size. Jon does offer longer tubes to fit XL size (45mm) cartos as well. In addition you can use longer cartos on mods where the tank may interfere with the button operation, or if you have any other reason for the carto to stick out the bottom of the tank a bit.
this post here will take you there JCB1 go look around there and let me know if you need more help would be happy to!
