This is a single item for sale. There are no noticeable stains or damage. It has been cleaned with a disinfectant wipe. The zero-magnetic field coil regulates the disruption of bioelectric currents. It utilizes a zero-magnetic field created by a two-layer coil, which helps to regulate the disruption of bioelectric currents. Silicone pad. Fits the sole of your foot for a light feel. You can also use it as a lesson tool. Thank you for viewing.