I have 4 Kanger SubMini tanks in my aresenal of vaping equipment. Well today when switching loads of laundry my mod fell out of my pocket and well the Pyrex on my Kanger SubMini cracked. When I tried getting the broken Pyrex off I cut the thin o ring closer to the bottom of my tank. I tried the replacement o ring from every box I had and they where all too big and I couldn't get the Pyrex back over the replacement o ring. These are the extra o rings that came in the bottom of the box. Just wondering it there is a trick to get them to shrink? Or could it be just a bad batch of o rings? I am going to order replacement one from Kanger this week.