Fan duct 50mm for buda's nozzle and greg wade extruder

Hi , I have searched a lot for a fan duct for Budaschnozzle with Gregs Wade Extruder but I have not found one that I liked, so I designed one. Based on these:
http://www.thingiverse.com/thing:257667
Use with 50mm fan.
I made it in PLA but next I will do in ABS .
I coated the part near the hot zone with Kapton tape to prevent overheating and warping.