The MOD-WII-ICSP can be used with a MOD-WII you purchased with UEXT connector to switch to ICSP connector. The WII NUNCHUCK is a controller for the Wii game console. It has a 3-axis accelerometer, a X-Y Joystick and two buttons. All these features are available through I2C communication, which makes it perfect for connecting through ICSP connector. As these controllers are mass produced for the game industry, they are at an incredibly low cost for the features they offer.
This small adapter might be connected to MOD-WII so the data is conveniently led via I2C to a small (1.25mm step) and a big (2.54mm step) ICSP connector