My initial reaction to receiving this product was confusion. I'm not sure if it's the merchant or product's fault, but it just came to me in a clear plastic, unsealable bag, and all the parts had just fallen out of it and were bouncing around the delivery envelope. The instructions that came with it were not intended for my product or were half-assed, as it did not explain how to use the metal, screw-on plate and the parts that came with it (2 small metal pieces that took me awhile to figure out on my own what they were for...and even now I'm still not sure what they do exactly). The picture also shows there being two plastic plates, but I only got one. I think they may have sold me a refurb or something, I don't know.
That aside, what I did receive works well. You can just replace one of the screws on your computer chassis and thread it through the metal plate, clamping it to your computer. You can't get to the screws without the key. I didn't use the plastic plates, as they look like a weakpoint. It would be better if they were metal perhaps. Instead I just looped the whole cable around an unmovable object.
I doubt this cable would put up much of a fight if someone came prepared: bringing a bolt cutter.