Each gauge lists both crochet hook and needle in standard us and millimeter size With a ruler in inches and millimeters, you can easily determine the size of the sweater or socks you have knitted Quick & accurate hook and needle measurements, check your crochet hook and knitting needle size with perfectly calibrated gauges Small in size for easy storage and travel to easily store in a handbag The sewing and knitting tool ruler is perfect for tyro to begin sewing on their own with the help of ruler, Manufacturer: LiRRvb