HELLA Side Marker Lights. Side marker lights are an important safety feature that make the outline of a vehicle more visible to other road users, especially in the dark - particularly useful for vehicles with large dimensions such as combine harvesters, long transporters, etc. In some countries, active side marker lights are required by law from a certain vehicle length. HELLA side marker lights meet the highest requirements even in demanding fields of application and impress with their durability and the well-known premium HELLA quality.