There is a white colored circle on the bottom of the pods in a doughnut shape. When the original pod is heated the white turns brown. I've tried re-using the pods by using white nail polish to cover the brown and also tried several layers of white out. I managed to get the machine to operate...
I joined just to make this single comment. I won this wisp vaporizer at a customer appreciation day 2 years ago at a massachusetts dispensary. I thought it was wonderful but was disappointed that its a "single use" pod and they did not sell empty pods to fill on your own. Since it was a start up...