Ab King Pro does work, if used correctly. As with any fitness device there are pros and cons to consider, before purchasing. Ab King is a folding workout bench with a moving arm to strengthen your abdominal muscle groups. The device includes multiple resistance settings.
Ab King Pro allows for a 200 degree range of motion to work and define your abdominal muscles. When used properly, you can work your upper, middle and lower abdominal muscles, and your outer oblique muscles. There are other exercise devices and workout routines to work these core muscles. Consider multiple options and read online reviews before purchasing.