How do you know which newer racket head guards would be suitable for the older ones? Are there any sources which shows which, let's say Wilson series is the newer one of another? I know k-factor comes after n-code and have kind of similar frames, and grommets. I need to order a new one for my k-factor racket, but couldn't find any solutions yet. (I want to order other items, too, from TW, so I need to find an alternative out of the ones that are sold on tw-store).