CHIAOGOO SWATCH/NEEDLE GAUGE SQUARE
This double-sided US/metric Swatch/Needle Gauge Square is a useful measuring tool for your knitting and crochet projects.
Use it to check the tension/gauge of your swatches (yes, we all should do swatches!), take measurements and size your knitting needles and crochet hooks.
The cut-out section allows you to accurately measure your stitch and your row gauge.
Metric/US ruler Knitting needle conversion chart Crochet hook conversion chart.