Keeps your Raspberry Pi attached to your Printrbot Simple Metal. The clip attaches to the frame from the bottom. Choose the 17mm clip for the sleeve Raspberry Pi case: http://www.thingiverse.com/thing:604915 And the 14mm clip for this slim case: http://www.thingiverse.com/thing:400624 The clip needs some clearance on the bottom and assumes you have feet on the corners to raise the Printrbot a bit for the clearance. The clip accounts for the curve of the Printrbot bottom frame with a sloped bottom floor. Print at 2 shells and 20% fill to give the clasps rigidity and strength.