I’d say you had to be there, but truth is these can still be bought online. From Wikipedia: "The Power Pad accessory is laid out in front of the video display for various games, generally plugged into the second NES controller port, with players stepping on the large buttons to control gameplay. There are two illustrated sides to the pad: Side A, which is rarely used, has eight buttons, while side B has 12 buttons numbered from 1-12." What the guys in the video are doing with it I have no idea.