The Elring Valvetronic Eccentric Shaft Actuator Seal (product number 250890) is a seal designed specifically for use with Valvetronic eccentric shaft actuators. This seal helps to prevent leaks and maintain proper functioning of the actuator, which is responsible for controlling the variable valve lift in an engine. It is made by Elring, a reputable manufacturer of automotive seals and gaskets. This product is essential for ensuring the efficient and reliable operation of the Valvetronic system in a vehicle.