FROM THEIR WEBSITE:

“Shape N Tone by Sport Elec target the entire abdominal area, unlike traditional crunches. The Sport-Elec belt stimulates the nerves that work the body’s muscles. The result is strong deep, yet comfortable, contractions that, over time, train your muscles to be firmer and stronger, while you work, play, exercise or relax! With 30 levels of intensity whether you are a beginner or a fitness elite there’s a perfect workout just for you.”

http://www.asseenontv.com/ab-belt-by-sport-elec/detail.php?p=296685&v=best-sellers#tabs