Note: For games which are specifically enhanced by New Nintendo 3DS Hardware, which includes similar control additions. See New Nintendo 3DS Enhanced.
The Circle Pad Pro is a 3DS accessory that was released in Japan on December 10, 2011. This was timed to the release of Capcom's Monster Hunter 3 (tri) G and was sold both as a bundle with the game and as a stand-alone product. At the time of its release, it retailed for 1,500 yen. The device requires one AAA battery in order to function. The Circle Pad Pro adds functionality for a second analogue circle pad, as well as additional shoulder buttons on the back of the device.
The Circle Pad Pro launched alongside Resident Evil: Revelations in North America on February 7, 2012, in Europe on January 27th, 2012, and Australia on February 2, 2012. In the U.S., it was released exclusively through Gamestop; in Europe, the device was released in a bundle with Capcom's Resident Evil: Revelations; and in the U.K., it was sold exclusively through the online retailer Zavvi.
Along with their 3DS XL announcement, Nintendo also confirmed that an XL version of the Circle Pad Pro would be available for the redesigned system starting November 15, 2012, in Japan. A European release followed on March 22, 2013. The Circle Pad Pro XL was only made available in North America via Nintendo's official online store for $19.99 starting April 19, 2013.
The New Nintendo 3DS and New Nintendo 3DS XL, released in 2014 and 2015 in various territories, features the extra shoulder buttons of the Circle Pad Pro as well as a "C-Stick" above the face buttons. The new system is backwards compatible with all Circle Pad Pro titles. Games designed with New 3DS enhancements in mind, such as The Legend of Zelda: Majora's Mask 3D and Code Name S.T.E.A.M., largely also have support for the Circle Pad Pro, though there are some exceptions such as Super Smash Bros. for Nintendo 3DS due to the New 3DS being more powerful.
The Circle Pad Pro communicates with the 3DS through infrared transmission rather than a direct physical connection. The battery life of the device is said to exceed 400 hours for a single AAA (packaged in with the device). When inserted into the device, the 3DS is incapable of being seated in its charging cradle, and it must be removed from the accessory in order to swap out game cartridges, the SD Card and the stylus. The device features three shoulder buttons; an additional standard R button that can be used in the place of the in-built R button for the Nintendo 3DS which becomes more difficult to reach due to the extended width of the system, and a set of additional trigger buttons labelled ZL and ZR, similar in nature to the triggers buttons found on the Wii's Classic Controller Pro. It also comes packaged in with a wrist strap that can be attached to the front of the device similar to Wii Remotes.