Interchangeable Circular Needles: Made from fine-grade aluminum, KnitPro Smartstix Interchangeable circular needles are lightweight and are a joy to work with. The perfectly crafted metal tips, and the smooth finish of the needles, enable effortless knitting. Available Needle Sizes: KnitPro Smartstix Interchangeable Circular needles are color coded and available in 9 popular sizes, ranging from 3mm to 6mm, perfect for knitting circular items like caps, beanies, cowls and even flat projects like blankets. 2-in-1 Knitting Tool: Smartstix is a perfect tool for smart knitters, who prefer precise knitting with accurate measurements. Each Smartstix needle is laser marked with a 2cm gap that lets you measure the gauge as you knit, making it a knitting needle and ruler in one. Laser-Printed Sizes: Each pair of knitting needles has laser-printed markings that set them apart from other metal knitting needles. These precise markings do not rub off due to friction of the yarn or the hands of the knitter. Sustainable Paper Packaging: Packaged in FSC-certified recycled paper, these needles prioritize sustainability with responsibly sourced, plastic-free materials to help protect the environment.