Pre-Owned Cybex VR2 Selectorized Ab CrunchSelectorized machine, with a 205 lb weight stack, is designed to strengthen the abdominal muscles of the torso during Strength Training. When using an abdominal machine the user is seated with a pad held to the chest and the feet braced, and lifts the loaded or selected weight by flexing the abdominals and pushing the pad toward the knees in a crunching or curling motion.