Just thought' I let you guys have A look at my really nice China LEDs and some other stuff.
The FYM220 9,99€ replacement filter has to be closed on the bottom (I used some PET lid just cut the edge of So' it fits smoothly with 4 Short stripes of duck tape) otherwise it's a tunnel. If you done that you can just place A heavy & good, industrial quality no name china 35,90€ 300m³/h tube fan model on it, fits perfectly ! but I also added some foil ... just in case. PS an LED Dimmer *(socket adapter) is a good airflow regulator just plug your vent' into it. Works seamless 🙂