Perform sit-ups and crunches easily effectively and safely with full range abdominal resistance. Achieve a 6-pack and toned tight obliques in less than half the time of other systems .Curved back is specially designed to place you in an automatic pre-stretch position. Full-range motion adjusts from 30 degrees back of center to 30 degrees forward of center for the ultimate in comfort and efficiency. Back pad is infinitely adjustable for a customized workout that is appropriate and safe no matter your size. Perform triceps extensions with ease in addition to abdominal workouts. For smooth operation and freedom of movement the ball bearing pulley is both extra-wide and sealed. Lightweight and easily moved.