The Nintendo 3DS add-on Circle Pad, apparently dubbed the "Circle Pad Pro" in the West, runs on a single AA battery.
How long does that battery last? According to a one individual in Japan who already has the upcoming peripheral, the device's instruction booklet says batteries will last around 480 hours.
If true, that's impressive and eases the headaches of buying batteries for this. It does nothing for the way the thing looks.
The Circle Pad Pro also comes with a strap, visible in the above photo. In case you want wear this thing on your wrist.
The add-on will cost ¥1,500 (US$19), and it will be released in Japan on December 10.