It fits the Standard Anycubic hotendbox and my improved one with or without BLtouch.
https://www.prusaprinters.org/prints/47884-anycubic-i3-mega-hotend-fan-box-also-mega-s-mega-x
To fix it to the printer use zip ties.
https://amzn.to/3lEAf80 this is the used fan.
I printed it with 0.2mm layerheight without supports - Material ASA or ABS
V4 with air splitter
The author remixed this model.