This needle gauge by ChiaoGoo is a handy accessory to determine the size of your knitting needles or crochet hooks – particularly indispensable for knitting needles without a button or circular needles without a needle number, but also a great tool to have, if the needle number has faded over the years. This needle gauge is made of durable, white plastic and is equipped with a ruler, with a measurement in centimetres (up to 13cm) on one side and inches (up to 5in) on the other side. The needle size is indicated in millimetres and in American knitting needles and crochet hooks sizes (from 0 to 15). This needle gauge is suitable for needle sizes 1.50-10.00mm.