Using these ChiaoGoo RED Lace Circular Needles is a breeze. Just pick up your yarn, cast on your stitches, and start knitting. The smooth surface of the needles and the red - nylon - wrapped cable make the knitting process very fluid. When it comes to maintenance, simply wipe the needles with a soft, dry cloth after each use to keep them clean. Avoid using harsh chemicals or abrasive materials as they may damage the needles. Store the needles in a cool, dry place to prevent rusting. As for the non - standard US 17 size, be aware of its actual 12.75mm measurement when planning your projects.