Slendertone flex is a clinically proven high intensity abdominal muscle toner in independent clinical trials 100 of users reported more firmer more toned abs 49 increase in abdominal strength 72 increase in abdominal endurance and 3 times more effective than its nearest competitor slendertones patented technology mimics the bodys natural muscle movement signals are sent to activate the nerves delivering a complete abdominal workout to the rectus oblique and traverous abdominus m