The rain sensor is an automatic moisture-activated system that detects how hard rain or snow is falling on the windshield and determines when to activate the windshield wipers. Dorman Rain Sensors are quality-engineered and designed to monitor periods of heavy rain or snow to increase the speed and rate of the wiper blades. Additionally, our rain-sensing sensors have undergone our industry-leading evaluation process to ensure long-lasting durability and trouble-free performance. This is an ideal replacement part for keeping your windshield clear and your vision of the road unobstructed.