Across Ebay, there are dozens of dealers that sell unopened, "guaranteed hot packs". Each pack will have either GU, auto, parallel, or whatever is denoted in the title. Anybody know how they are able to figure this out? I've heard that people have gone to the extremes of calibrating the thickness of the pack in millimeters, the weight in grams, etc etc. But what about auto's and parallel hot packs? It's a mystery I'm stumped on, and I'd like in on it thank you very much
Any thoughts, hints, secrets of the trade, or just general chatter on this?

Any thoughts, hints, secrets of the trade, or just general chatter on this?

Comment