The Knitter's Pride Mindful Collection Swivel Cords work with all types of Knitter's Pride needles and Tunisian crochet hooks! The stainless steel cores are coated with nylon so they have zero memory. That means no kinks or twists while allowing your stitches to slide easily. They are also marked at one-inch intervals so you'll never have to worry about forgetting your tape measure! Mindfully brilliant is what we call them!