ADDI Regular Circular Interchangeable Needle Set The addi Turbo Click system provides 10 different sizes of addi Turbo tips (3.5mm, 3.75mm, 4.0mm, 4.5mm, 5.0mm, 5.5mm, 6.0mm, 8.0mm, 9.0mm, and 10.0mm), three different lengths of our new, extremely pliable blue cord (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 Clicks revolutionary locking mechanism!