This is the bottom part of the OpenPilot CopterControl case. You also need the top part (Case upper v1) and (optionally) the base (Case base 1 v1). More info here: http://wiki.openpilot.org/display/Doc/CopterControl+case
IMPORTANT NOTE: Due to some very slight dimensional differences, this case needs some minor modifications with a knife/file to fit the CC3D. A separate version is available for the CC3D.