When I get home I'll post a pic of it but for now I'll try to describe it.
The current YHM FF assembly does not look like this, nor does it use the YHM tool. It has a outer ring that screws to the upper and a inner ring that screws inside the outer ring. By use of set screws, the outer holds the inner, which holds the barrel in. The handguard attaches to the outer ring by set screws with a head, like a wood screw has, flat topped but with an Allen head.