All right, so these are not rope, technically - they are something more akin to nylon cord. The nylon cord is looped around itself and fastened with rivets. There is also a connector buckle (like the sort of buckle you might see on a back pack) that attaches the wrist cuffs to the ankle restraints. All in all it reminds me of a piece of camping equipment more than a piece of bondage gear.
They'll hold you against some struggling though the narrow width of the cuffs and the fact that they tighten can make them uncomfortable and a bit risky in terms of circulation. I'd strongly caution you not to leave a submissive alone tied up with these no matter how easy to escape they may seem.
Other than that one flaw in their safety features they perform... reasonably. I recommend them to beginners if you like them for other reasons and are willing to be cautious.