3 mm boom and brackets

One of the prototypes for my fan duct for my hotend ( http://www.thingiverse.com/thing:190298 ) incorporated a boom and bracket system to position the duct to the hotend.
In the end I found the system flimsy and unreliable for that purpose but I thought someone might enjoy the boom and brackets that I was left with as a by product.

Picture uploaded.
Fixed error in description. The brackets are 3mm NOT 4mm as originally stated.