HK Alien 560 Electric Retract Mount
Designed for Electric Retract 18.8g.
Custom mounting plate fits exactly to original landing leg screw holes and screw heads.
[Updated : Improvement for lower resolution printers]
To see them in action :
https://www.youtube.com/watch?v=wUJgKzx_xvw
To buy them 3D printed with m2.5nuts :
http://www.ebay.com/itm/262161979947
Foot for 4OD3ID hollow carbon fiber tube :