The Bosch Glow Plug Kit - 472679 is a comprehensive kit designed for servicing a car's glow plug system. It includes various products necessary for a complete and effective maintenance of the glow plugs in a car. The kit contains a set of glow plugs, which are essential components in diesel engines that help with cold starting by heating the air-fuel mixture. It also includes a glow plug relay, which controls the timing and duration of the glow plugs' operation. Additionally, the kit contains a glow plug control module, which is responsible for monitoring and regulating the voltage and current to the glow plugs. Other components in the kit may include wiring harnesses, connectors, and other accessories for proper installation and operation of the glow plugs. This kit is an essential tool for ensuring smooth and efficient starting of diesel engines in a car.