Not necessary because of the customization of the tire cover. It is unique enough that if anyone else removed and tried to use it, would be useless. Also, the security kit was a bit difficult to apply. Had to secure it with tape from rubbing against the paint of the tail gate. Plus one of the grommets came away from the vinyl cover holes.
The security system is an unremovable thick cord, similar to a gun lock. It would have worked better if the tire cover was simply going over a spare. My tire cover went over a hard plastic cover, so I had to finesse the cord to ensure some security. I am still glad I added this to my tire cover, as the cord and lock make it more difficult to steal. The lock is as small as possible and just a nuisance to the thief. However, I am still happy with the security kit because it forces the thief to be at my vehicle longer. More effort means less likely to be taken? Hopefully.
The costly cover was augmented with a hefty cable to lock it securely to the vehicle. However a sub-par and frankly cheap luggage lock was provided that would not last 3 minutes to remove and steal the cover. I ended up buying a beefier lock and discarded the lock provided. If you're going to spend that much on a cable, spend at least that much on a good lock to go with it.
Fits and looks very nice!!