Yeh, what she said. Ive been using this glass and didn't know out side fume would work differently then iso, which is cool because i have a case and a quarter of 26mm tube that i gave up trying to fume on. I cant comment on the quality issues, ill leave that to more experienced members. The only reason i gave up fuming on it is because i tried simax and my combes actually came out and with this i couldnt get it. I bet a talented fume'r could learn how to get some new colors in their pallet using it though. Just because i cant do it, doesnt mean i dont believe it can be done.