The Body Solid Semi-Recumbant Dual Ab Bench will allow the user to increase or decrease resistance with weight plates for a better ab workout. Only Olympic style plates can be added to the plate holder. If your unable to do a set of crunches using your own body weight, you can simply add weight to the plate holder on the rear of the machine for assistance. This bench is so comfortable that they are built with extra thick and durable DuraFirm seat pads. This ab bench is also backed for a Lifetime of use by the best warranty in the industry.