I am writing this post, and must admit, I am quite LIVID! Vaped on my normal 12nic and realized that I definitely needed a lower nic level. So I swapped it out, glass was a bit hard to remove, but not too bad. Cleaned and dried it and put it back together and vaped on my new flavor for about 6 days. Decided to change out the flavor again. Repeated same steps above. This time however, the glass was a bit like it was snagged. So I tried to reverse the glass to let it settle back into place..... CRACK.... Then what went on for about 30 minutes was me trying to remove what broken glass I could. NO WONDER they give you an extra glass casing. It's almost as if they KNEW their design for holding the glass in place was terrible. Now I will never be changing flavor or cleaning this thing again (aside from changing burnt coils) and will be purchasing a Kanger SubTank in the future. Hope this helps others out there.