The DS 16 Six Game Changer plugs into the side expansion of Sega Genesis Model 1 & 2. By pressing the button attached to unit, you can switch between 6 different Genesis games. Sega installed these units into kiosks to promote Genesis games. Complete kiosks housing the Genesis and DS 16 Six Game Changer could be found back in the 90's at Kay-bee-Toys, Toys R Us and other retailers. The 6 Game Changer unit by itself was recently listed on ebay for $199.99.