I bought a Vision CE4 Version 2, but it is rebuild-able. tank, heads and mouthpiece all come apart. As far as I can tell, the Version 3 is rebuild-able. Is that the only difference, older Version 2's aren't rebuildasble, but newer ones are? I think I got a version 3 because it's rebuild-able, but it was just labeled vision CE4 version 2. So far, really digging it, waiting on my Spinner 1300 to get here and dial this in even more. As always, Thanks.