As you can see in the highlighted square box, there are three units in a row, these enclosures are a new device used by AGW Electrical to help save energy when using standard industrial high bay lighting like Sodium/Metal Halide or Fluorescent lighting.
These devices allow for the high starting current that discharge lighting produces and then switch over to a lower running current which still runs the lights at full brightness but uses 30-35% less electricity.
Obviously when a large industrial unit can have over a hundred light fittings the savings could be massive!
