Body Solid GAB100 Horizontal Ab Crunch MachineThe GAB100 is incredibly effective at isolating the entire abdominal region with one synchronised motion. The linkage bars allow upper and lower body movements in one biomechanically correct abdominal crunch. The unique patented design allows for variable weight resistance; there is a weight post to add more weight for more resistance and there is a counter balance weight post that will decrease resistance, making it perfect for users of any exercise