A simple adapter for the Petsfang or any similar fan duct that fits a 40mm fan. Designed to fit 60mm fans including the Noctua 60mm fan. If you are planning on installing a Noctua fan, I highly recommend you wire it and the mainboard cooling fan in series. That way your mainboard cooling fan is always on, you won't fry your mainboard during a long prints initial layers, and the Noctua gets the 12v it specifies. Printed in PLA, it isnt close enough to the heater block to melt or soften the plastic.
Uses two of the stock M3 screws to secure the adapter in place, 60mm fan flange is designed to have M3 screws threaded into it. It's easier to thread the screws in with it off the printer.