The URO Parts Headlight Bulb Cap - 015834 is a small plastic cover that is designed to fit over the headlight bulb of a vehicle. It is used to protect the bulb from dust, dirt, and moisture, which can cause damage and reduce the lifespan of the bulb. The cap is made of durable materials and is designed to be easy to install and remove. It is compatible with a wide range of vehicles and is an essential component for maintaining the proper functioning of a vehicle's headlights.