Using these Jimmy's SmartStix Interchangeable Needles is easy. First, pick the right needle tip size from US 2.5 to 11 for your project. Then connect it to the Jimmy's Smart Cord. When you're knitting, use the 1 - inch markings on the needle tips to measure your work as you go. You can check the gauge and wraps per inch easily. As for maintenance, keep them in a dry place to avoid rust on the aluminum. After use, wipe them with a soft cloth. Be careful not to bend the needle tips or cords too much, as this could affect their performance. Have fun knitting!