second monitor extension arm vesa75x75

Since i needed an extension arm for my second 15inch monitor i designed this arm. It should be mounted on the backside of the main monitor and hold the second monitor above (or below) the main monitor.

Things you will need:
long enough (3cm) M4 screws for mounting on the main monitor and shorter ones for the auxiliary monitor. 2 M4 nuts and short M4 screws for mounting the arm on the vesa100x100 plate.