The Vemo Engine Coolant Fan Temperature Switch - V15992008 is a sensor designed to monitor the temperature of the engine coolant. It is responsible for activating the engine's cooling fan when the coolant reaches a certain temperature, helping to prevent the engine from overheating. This switch is specifically designed for use in automotive engines and is made by Vemo, a reputable manufacturer of automotive parts. It is a reliable and essential component for maintaining the proper functioning of a vehicle's cooling system.