Components must be mounted inside the rover chassis, but cannot tolerate the oven-like heat of the belly pan. The belly pan faces down onto the illuminated lunar surface. Heat-sensitive components are not mounted directly to the belly pan. They are isolated by mounting on standoff cones that maintain a gap between the components and the hot surface.
Attempts to fabricate these cones from composites failed, due to the tight, complex curves. Fabrication from aluminum succeeded.

From AstroboticBlogPhotos