expansion slide pad

ign.com
Super Smash Bros. 3DS Will Not Support Circle Pad Pro - IGN

Nintendo of Japan has confirmed on its 3DS support page that Super Smash Bros. for 3DS will not support the Circle Pad Pro (also known as the Slider Pad or Slide Pad Expansion) attachment for the current 3DS and 3DS XL handhelds. Super Smash Bros. 3DS will, however, take advantage of the C-Button on the redesigned New Nintendo 3DS and New 3DS XL, both of which also feature an extra set of shoulder buttons.

gobble my glutes, nintendo