The plastic plate is used to determine the size of the knitting needle by test: if the crochet hook or knitting needle goes into the side cut and there is no space between the gauge and the needle, the needle is the size of the number written next to the cut. The plate has 13 places between 2 and 10mm on one side and between 0 and 15 on the other side in the USD systemSize: 9x6.5cmMaterial:plastic
