Odin offered:
I just wonder how much this useless piece'o junk (but cool juunk ) would cost. Can anyone read Japanese here? =)
;-) It's a USB Hot Coaster!
As described, it comes in orange, cool gray, navy, and silver.
The graph indicates the decline in temperature over time of a cup equipped with the hot coaster (red line,) and a cup without (blue line.)
The ad doesn't address the question of cost. This allows retailers to set their own prices, so shop around.