I've had the above in my accumulated kit for some years, but never used it as I thought it was a bit gimmicky.
Finally used it on a roebuck and a lamb last week.
Didn't need to sharpen it, it cleaned up very easily and I still have all my thumbs and fingers. This was the first skinning and butchering I had done on anything larger than an 8-foot python for 45 years.
The attachment is the actual knife.