Each squeegee blade (front & rear) can be used on all four sides for recovery of dirty solutions. You can use the front side of the squeegee, then rotate, so the back side is facing forward. Then, you can flip it upside down, and use both of those surfaces. No tools are required to switch your blades, which make it extremely easy, allowing you to do it fairly frequently. We recommend rotating your squeegees every 20 hours of scrubbing, so they wear evenly and last longer.