Using these Jimmy's SmartStix Interchangeable Needles is a breeze. Just pick the right size tip from US 2.5 - 11 for your project and pair it with the Smart Cords. As you knit, use the 1-inch markings on the tips to measure your work or check the gauge. When you're done, gently clean the aluminum needles with a soft cloth. Keep them in a dry place to prevent rusting. Avoid using harsh chemicals or abrasive materials on the needles as it might damage the color-coding and the surface.