I remixed the model from https://www.thingiverse.com/thing:5403201 by RenzoB that it is for old version of iliadbox (freebox free box) without wifi6.
The new model with wifi 6 is thicker. So I changed that size 42mm+0.2mm margin.
Thanks to this vertical stand the iliadbox's internal temperature decreases by at least 3°C .