Bigger Smok tf rta glass?

[liquidphantom]

Does any one know of anywhere selling bigger capacity glass for the Smok tf rta, like bubble tube or something similar. Failing that can anyone recommend an RTA where I can at least get a glass to give more than 4ml capacity? I love my Uwell D2 RTAs but the 4ml capacity is too small and I hate having to refill so much.