Do they let you pull the wheel away cleanly or something? Never heard of them!
You basically remove 2 bolts , and thread the spikes in they are around 6" long so take the weight of the wheel as it comes off of the center spigot.
I use them on all my cars with big brakes as it saves the wheel catching the caliper, but it's even more important with ceramics. If the wheel comes off the spigot and hits/chips the disk it can end up being an exspensive day.