This is the GE 90 fan cufflink with a bit of the casing. It's actually not the fan containment but part of the nacelle, which is actually much longer at the front. Since you couldn't see the fan anymore I made the lip of the nacelle close to the blades though. So scientifically this is inacurate but I made it for anyone who prefers the blades to be closed up by a smooth surface.
This cufflink is about 20mm total. That is why the fan itself is smaller than on the original cufflink that doesn't have the containment.
I have all my jet engine cufflinks with and without containment.