This is a fanduct for the E3D hotend that includes holders for 30mm fans to cool the print. The hot end cooling fan is 40mm and preferably a silent fan. I use a cheap fan regulator to tune the 40mm fan.I have used 3x16mm screws for plastic but you might just as well tap and use ordinary M3 screws to fasten the fans or any other 16-20mm screws. Ledpanel is fixed using double sided foam tape.40mm fanhttp://www.ebay.com/sch/i.html?_nkw=40mm+silent+fan30mm fanshttp://www.ebay.com/sch/i.html?_nkw=30x30X10mm+case+fanLed panel (Spilt in two)http://www.ebay.com/sch/i.html?_nkw=16+led+panel+5050Screws for plastichttp://e3d-online.com/RepRap-Spares-Mechanical/Fixings/Plastifast-ScrewsFan speed regulatorhttp://www.ebay.com/sch/i.html?_nkw=12V+fan+speed+regulator