Windshields protect the vehicle's occupants from wind and flying debris such as dust, insects, and rocks, and providing an aerodynamically formed window towards the front. UV Coating may be applied to screen out harmful ultraviolet radiation. On motorbikes their main function is to shield the rider from wind, though not as completely as in a car, whereas on sports and racing motorcycles the main function is reducing drag when the rider assumes the optimal aerodynamic configuration with his or her body in unison with the machine, and does not shield the rider from wind when sitting upright.