Bottle bracket for windowfarm

I used this thing to connect a bottle to a rod for building a windowfarm. The bottle contains the plant pot. A picture is here
http://farm6.staticflickr.com/5531/9210101347_e4b426219b_z.jpg

All sources can be found here:
https://github.com/schub/basteln/tree/master/windowfarm

A how to for building a windowfarm can be found here:
https://github.com/schub/basteln/wiki/Windowfarm