This chandelier rose consists of a bar with a loop either end and a cup which slides up and down in between.  The top of the bar loops onto a hook already fixed to the ceiling (see our comparison chart to choose the right hook, if you are looking to buy one).  The cup then slides up to cover the hook and is held in place by the collar with a locking screw. The loop the other end is connected to the chain for the light fixture. The triangle loop within has an earth terminal.