First I've seen of them, but I've only been vaping a couple of months, and I don't think they've made it to this side of the pond, but I do know that my metal ones sometimes get quite warm, I don't think I'd like to be around a plastic one if it were to vent, especially as there are a lot of idiots out there who know nothing about battery handling, I've seen a lot of burns in my life and they are not pretty.