Hi Tenblade
The fans they sent me are these if it helps.
http://www.cmstore.eu/cases/cosmos/cosmos-ii/120mm-led-fan-on-off/They say they are compatible with the Cosmos II case
and support confirms this.
I have at this moment just installed two GPU fans on the door
these are the new ones they sent me these are in black one worked fine the other
started doing the same thing slowing down speeding up.
I took it off and found that the fan blades would pull off
after checking all the 7 new fans two of them, the blades would just pull off,
the rest are all fixed very strange?
I think another email to support is in order
By the way there are 3 settings on the fan controller on full power you would not notice anything wrong
on slow speed and medium it is very noticeable the speed variation that is.
Many thanks for your reply Tenblade.
Bottlegone.