FIG. 8 depicts an implementation of the metal extrusion 62 included with the assembly. The overall structure of the metal extrusion 62 and the cooling conduits 26 can be formed by extruding metal through a die as is described above. In some implementations, cooling fins 30 can be formed in the metal extrusion 62 that extend into the cooling conduit(s) 26. The cooling fins 30 can have a cross-section that is defined by the die through which the metal is extruded. The first end cap 14 and the second end cap 20 can be attached to the metal extrusion 62 in a fluid-tight manner to enclose and partially define the cooling conduit(s) 26. The first end cap 14 can be attached to a first end 32 of the metal extrusion 62 so as to close off the first open end 34 and define at least a portion of the fluid conduit(s) 26. The second end cap 20 can be attached to a second end 38 of the metal extrusion 62 so as to close off the second open end 38 define at least a portion of the fluid conduit(s 26). The first end cap 14 and the second end cap 20 can be attached to the metal extrusion 62 in a variety of ways that have been describe above. In this implementation, the metal extrusion 62 includes two fluid conduits 26a, 26b. And the first end cap 14 includes a conduit divider 40 that separates a first fluid conduit 26a from a second fluid conduit 26b. The first end cap 14 can include a fluid inlet 16 that is in fluid communication with the first fluid conduit 26a and a fluid outlet 18 that is in fluid communication with the second fluid conduit 26b. The fluid inlet 16 can be separated from the fluid outlet 18 by the conduit divider 40. The width and height of the first end cap 14 and second end cap 20 can closely conform or match with the width and height of the metal extrusion 62.