After the main friction zone, some car washes have a dedicated care zone. Prior to entering the care zone, the car is rinsed with fresh water. This is immediately followed by a series of extra services. In many car washes, the first of these services is a polish wax. After the polish wax application is typically a retractable mitter or top brush and, in some cases, side brushes or wrap-around brushes. Next is a protectant, which creates a thin protective film over a vehicle's surface. Protectants generally repel water, which assists in drying the car and aiding in the driver's ability to see through their windshield during rain. A low-end wax or clear coat protectant follows the main protectant. A drying agent is typically applied at the end of the tunnel to assist in removing water from the vehicle's surface prior to forced air drying. After the drying agent, there may be a "spot free" rinse of soft water, that has been filtered of the salts normally present, and sent through semi-permeable membranes to produce highly purified water that will not leave spots.