Knit Pro (Knitters Pride) interchangeable stainless steel cords are coated in a smooth black casing. Strong and flexible with a smooth join which enables your stitches to slide effortlessly. Each cord comes with a tightening "key" and 2 end caps to keep your knitting safe if you have to use your tips on another project. Cord measures 8" to make an approximately 16" circular needle when paired with the 3.5" long needles tips.