Using addi Turbo Circular Needles is easy. Just thread your yarn onto the needle and start knitting as you normally would. The nickel - coated surface allows the yarn to move smoothly, so you can work on your project without any hassle. When it comes to the non - standard sizing, make sure to double - check the actual size before you start your project. As for maintenance, keep the needles clean and dry. You can gently wipe them with a soft cloth after use. Avoid bending the cords too harshly to keep them flexible. And since the US 36 and US 50 needle tips are plastic, handle them carefully to prevent breakage.