two brackets each side, they go under the tail gate straps, using the o/e bolts, cant be seen at all with gate shut.
Then cage drops in from the top, the two round bars have a flat side, top and bottom, so when you swing it back its locked or forward its locked in position, only way to quick remove is have it vertical, then un clips, its so easy and very clever.
small adjustable strap then clip to gate strap, so it will not lift, made from alloy, very light, but very strong.
on the image, if you expand it, the center rail is were it connects to the truck.
hope that helps, not easy to describe, I will try some more pics, but have removed the brackets now