Using these Jimmy's SmartStix Interchangeable Needles is super easy. Just pick the right size needle tip for your project. The color - coded and marked design helps you measure as you knit. You can use it to measure the length of your work or check the gauge. When you're done with a project, gently remove the yarn from the needles. To clean, you can use a soft cloth to wipe them down. Keep them in a dry place to prevent rusting. Be careful not to bend the aluminum needles too much as it may affect their performance. And if you want to change the needle tip for a different size, simply follow the instructions that come with the set to pair it with the Smart Cords properly.