Resilient, flexible cords lay flat and won't kink or twist. Easy to store, smooth to join. They enable stitches to slide around your needles effortlessly. Long threaded screw-in “join” insures that cord and needles stay connected. Tightening hole provided in the metal join for extra secure tightening. Specially designed “key” facilitates effortless tightening. End caps easily fit on cord and keeps knitting safe. They fit any of your Knitter's Pride interchangeable circular needle sets.