GPS Mount (Copter / Plane) for (APM / NAZA DJI / Pixhawk, ...)
This is a small evolution of the GPS Mount http://www.thingiverse.com/thing:256474 to add the 4mm cylinder.
The rod is 7 cm high and can be easily cut to adjust the length you need.
I advise to let 3/4 cm which is a quite good length.
The base could be attached with 2 rilsan collars to the leg of the copter.