MAKE SURE TO MEASURE! Every printer is different! This thing fits MY printer great but yours might have a different nozzle height, different heater block orientation, etc. Combined these two things: http://www.thingiverse.com/thing:71073 http://www.thingiverse.com/thing:254004 So you can use this awesome part fan mount/duct with a 40mm fan. I uploaded the original fan duct from the source. I did not edit it, I only uploaded it for convenience. I take no credit for its design.