This sturdy, white resin, multi-purpose, laser cut look is used to determine gauge and help measure you needle/hook sizes. In addition, there are handy conversion charts and yarn standards tables for reference. Simply place the tool on your swatch and count how many stitches/rows fit inside the cut-outs (along the bottom for stitch gauge and up the side for the row gauge.) The tool is double-sided for US/knitting vs. metric/crochet differentiation. Made in the USA. Measures approximately 5.5" (14cm) square.