Installing 3d printed fan duct

[Logitechbro]

Hi everyone,
I'm putting a dancase together and started attaching the fans. How do I screw in a 3d printed fan duct onto the noctua l9a?
It seems the screws already in the noctua fan are not long enough and there are additional screws that seem too long. Does anyone know which length and kind to get?
Thanks

 

[Logitechbro]

Looks like the place I ordered it from forgot to send the new sized screws. They're a slightly longer m3.