Cooling fan for Wanhao Duplicator 4

This is a cooling system for Wanhao Duplicator 4 (the exact chinese copy of Replicator 2X) that improves the print quality.for me it was almost impossible to print bridges and overhangs,but after mounting these fans life is a little bit easier ;)
No printed elements need to mount the fans.
I also included a little bridge test model (about 4 cm length) to compare your print quality before/after using these fans.
It worked for me, so i hope it works for you too.