Bosch Engine Cooling Fans provide sufficient flow at idle, so your vehicle doesn't overheat while sitting in traffic. They operate with minimal noise, preventing the heterodyning effect (combination of two sound frequencies that result in uncomfortable noise for vehicle occupants) common with lower quality and less expensive competitor cooling fans – and the blades are balanced, ensuring safe and durable performance. These cooling fans also have protective functions integrated into the electric drive – like automatic shutdown, in case of any obstructions, and thermal fuse and reverse polarity protection.