u/QuackinOutLoud

For context, I’ve been wanting to buy one of these for a year now and found one on eBay at a good price. Anybody here ever used one? If so are they worth it?

Really not sure what exactly it is, someone asked if it’s a burn but I don’t remember burning myself in the last 24 hours. It doesn’t hurt either and I’ve tried scrubbing it off in the shower and with dawn dish soap but nothing. Any ideas?