Layer board and a top with the kubernetes logo for creating a RaspberryPi 2 stack.
You will need a nice set of 2.5mm plastic / metal spacers with adequate nuts and bolts.
Print with a bigger infill percentage to ensure the boards will be strong enough.
The kubernetes logo is taken from the open-source repository on github: https://github.com/kubernetes/kubernetes/blob/master/logo.svg and converted to STL via http://svg2stl.com/.
A brim will be nice, cause it will prevent the edges from warping and thus making a non-flat board.
Print with higher infill, and lower speed on the initial level to make sure that the details are printed nicely (especially the holes).