https://www.zettlernb.com/products/5-pin-automotive-relay-jtkw/ The JTKW 12v 40 amp 5 pin relay is a type of electro-mechanical switch commonly used in automotive applications. It is designed to handle high current and voltage loads, and can be used for a variety of purposes such as turning on and off headlights, power windows, wipers, and other electrical components in a vehicle.