The Bock RLM series is iconic in both style and functionality. First developed in the early 1900’s to replace the individual overhead lights traditionally used in warehouses and factories, the RLM light fixture, most often characterized by its spun metal reflector and white interior, offered a more efficient lighting solution that provided a broader distribution of light. In 1919, a standard was developed to specify minimum requirements in efficiency, safety, and quality for these types of fixtures. It was called the RLM Standard Specifications for Industrial Lighting Units. The Spero RLM fixture was one of the fixtures to earn the approval of this original lighting standard..