Wii Nunchuk

The device plugs into the bottom of the Wii Remote and provides two extra buttons (C and Z), an analog stick, and motion controls of it's own (although aren't as precise as the Wii Remote's motion controls).

The Nunchuk came in several colors and was used for a large amount of the Wii's library, and was also usable on the Wii's successor, the Wii U. It also came with Wii consoles.