The addi Lace Click system provides 8 different sizes of addi Lace tips (3.5mm, 3.75mm, 4.0mm, 4.5mm, 5.0mm, 5.5mm, 6.0mm, 8.0mm), five different lengths of our new, extremely pliable blue cord (16", 20", 24", 32" and 40"), and one connector piece which helps to either store stitches or combine your cords. The Click tips require no tools to change; simply insert the cord deep into the tip, twist and release. The tips will remain secure until you change them, thanks to the Click revolutionary locking mechanism! The addi Lace Click tips are nickel plated. Our nickel plating process is electro-static, which produces a smooth, rounded edge, where the tip and the cord "click" together. Please note, this plating is only added to the Lace Click tips, and not to our regular addi Lace circular needles. Also, these specific tips have been shortened by 2 inches, to allow for the use of shorter cords (to make 16" and 20" possibilities).