Easily increase the resistance of your Stamina AeroPilates reformer. When you replace the existing black cords in your Pilates reformer with Stamina AeroPilates Power cords, you"ll increase the force of resistance by 40%. Installation is quick and easy with the included instructions. This is an excellent way to add new challenge to your Pilates routine. * For use with any Stamina AeroPilates reformer * Increases resistance force by 40% * Elastic cord with nylon cover and plastic knob * Quick, easy installation- simply replace existing black cord * Includes installation instructions * Manufacturer"s warranty included (see product guarantee)