Using this needle gauge is a breeze. Simply insert your knitting needle into the holes until you find the one that fits perfectly. That hole will tell you the size of your needle, whether it's in US or metric measurements. As it's made of natural bamboo, avoid getting it wet for long periods to prevent warping. You can gently wipe it with a dry cloth to keep it clean. Store it in a dry place when not in use to maintain its quality.
