IIRC the Silhoute is the same thing as the Beeman Ram Jet. The new Ram jets are shown with a smooth skirt, whereas the older ones I had were ribbed. I believe they we included in your .177 cal sampler. I have only tried the .22 version, I found them to be decent accuracy wise, but nothing special. That doesn't mean they will not work well in your CFX.
Regards
Nathan