The peripheral is designed like a cradle, which attaches onto the base of the 3DS. It adds a second circle pad which will be located to the right of the ABXY buttons. This accessory will also increase the thickness of the system by a few centimeters.
A scan from Famitsu showing off the second circle pad.
The accessory is officially named the "Expansion Slide Pad." No pricing details or a release date have been given.
Monster Hunter 3G will be an enhanced version of the Wii's Monster Hunter Tri. The game will "include a few changes to the world" as well as having new content. Underwater gameplay will be present in the 3DS version, although the controls are slightly modified. Touch controls and local wireless multiplayer were also confirmed. Nothing too specific was revealed, but it is currently slated for a Japanese release by the end of the year, and will be playable at September's Tokyo Game Show.
Famitsu also interviewed Monster Hunter Producer Ryozo Tsujimoto, who described the new accessory as the 3DS's "secret weapon." The second slide pad will be used to imitate the gameplay experience of the console version.
It is currently unclear whether the second slide pad is being made specifically for Monster Hunter or any other specific titles.