Some "Fang" fans need to be secured on their visible side, just to avoid damaging the blades while the fan is rotating.
Here is a small protective grid placed, in my case, on the 2 NOCTUA 40x40 fans that equip my heating head and the nozzle.
I didn't add a nozzle around it because I consider that it could disturb the incoming air flow. The NOCTUA are efficient enough to do without this artifice.
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