I'm not really sure why someone would need/want these hooks. According to the product description the hooks are to "allow you to position the bridle and reins at the best position and keep them stabilized in that position."
But really, what does that mean?
Do I have to use the hooks?
What if I use the hooks, what will that do for the action of the bit? Do they increase leverage or something?
Here's a link to the bit in question:
FES Ported Barrel Dee in D-Rings at Schneider Saddlery