It is not really necessary. I was going to add this to my setup & I found it was going to be hard to reach. It keeps the jetpack from swinging from side to side but unless you are doing stunts it is not really a concern. A piece of Velcro there would serve the same purpose. I actually put a bit of weatherstripping on the back of my pack so it doesn't rub against the back plate & it provides enough friction that the pack doesn't sway.