The Smartpool NC22 Robotic Pool Cleaner Foam Ring is positioned between the pair of Drive Brushes. The Ring provides additional traction to propel the Cleaner along the flat surfaces of the pool. When the Foam Ring wear down to the point where it has minimal contact with the pool surface, it has to be replace. This guide provides step-by-step instructions on how to replace this Foam Ring. Note: Although this guide features the NC22 model cleaner, these instructions can be used for replacing the Foam Ring on other models of Smartpool Robotic Pool Cleaners that use a Foam Ring.