1 - 3.5" disk drive magfnet, Mine measures 40x20x3 mm thats with a bit of slack
2 - m3x10 socket head screws.
4 - M3 hotmelt inserts to mount the fane
4 - M3 x 12 screws for fan
watch the print, once the pocket for the magnet is nearly complete, pop drop the magnet in to the recess. the head should clear once there is only a layer or 2 left before it seals up the recess.
Once dont printing, attach your fan, screw the 2 bolts into the fan mounting holes and tighten till flush.
The fan will then just pop onto the heads that are sticking out.