Using these Jimmy's SmartStix Interchangeable Needles is a breeze. Just pick the right needle tip size for your project. Since they're color-coded, it's easy to find the one you need. The 1-inch markings on the tips let you measure your knitting as you go. You can measure gauge by counting the stitches and rows within the marked area. For different projects, pair the needle tips with the appropriate Jimmy's Smart Cords. When you're done knitting, simply remove the needle tips from the cords. To keep them in good condition, store them in a dry place. Avoid bending the aluminum needle tips as it might affect their shape. If they get dirty, you can gently wipe them with a soft cloth.