Your Stamina Pilates Reformer is easily upgraded to add resistance to your strength training goals. This cord adds 40% more resistance than the original cords included with your Stamina Pilatse Reformer. Replacing the cord on your reformer is easy and i Suitable for use with any Stamina Pilates Reformer, these two cords each provide 40 percent more resistance than a Reformer's standard cords, permitting a user to raise strength-training goals. Instructions are included to easily substitute these cords for standard cords.