In one implementation, the cover 22 can attach to the metal extrusion 12, the first end cap 14, and/or the second end cap 20. The cover 22 can be a separate element that encapsulates the electrical circuit components 24 and protects them from external harms, such as heat, dust, or moisture, to name a few. In this implementation, the cover 22 is a discrete element that can be affixed to the auxiliary-cooled electronics assembly 10 as shown in FIG. 1. The cover 22 can be stamped from sheet metal or cast out of metal and include physical attachment points 46 where the cover 22 can be affixed to the assembly 10. The cover 22 can be attached using mechanical fasteners, such as screws/nuts or rivets, or pivotable clamps that releasably attach to the metal extrusion 12, and have levers that engage the cover 22 and compress it against the metal extrusion 12. In some implementations, the cover 22 can be molded from a composite or plastic. The plastic or composite can be made of an electromagnetic field (EMF) shielding material. For example, an EMF fabric can be molded into a composite material forming the cover 22. The EMF shielding material can form a Faraday Cage around the electrical circuit components 24. Further, the cover 22 can include one or more openings 48 that can accommodate electrical inputs or outputs, such as a power supply or an electrical control signal output, in the form of a male or female electrical connector 50 that can receive a corresponding male or female plug.