knitting needle gauge

A knitting needle gauge is used to determine the size of a knitting needle. Some also double for crochet hooks. Most needles come with the size written on the needle, but many needles (like double-pointed needles) tend to not be labeled. Also, with wear and time the label often wears off. Needle gauges can be made of any material, and are often made for metal and plastic. They tend to be about 3 by 5 inches. They contain holes of various sizes, and often have a ruler along the edge for determining the gauge of a sample.