Here's a little annoyance I just discovered. Took it down for a new coil, washed stuff, and decided that with it disassembled, let's try that black color changing glass. Now I ran that glass under hot water and sure enough, it went clear, pretty cool. Put it back together, and it looks really slick with the black glass and black trim. Vaping away, granted only 50W, but chain vaping, and the glass is still black! It never gets hot enough to change to clear. Which now really stinks as I can't see my juice level. Back to clear when this tank runs low. Would have been fun if it worked. OTOH, I guess it's good to know the tank never gets hot even when chain puffing.