Travel size knitting needle gauge tool. Made from from PLA, a 100% biodegradable, plant-based plastic substitute! Each disc is imprinted in both US and mm needle sizes from US 0-15 / 2-10 mm Overall size (closed) is approximately 1" diameter X 1.5" high (2.5 cm X 4 cm) We have long wanted a tiny needle gauge tool for travel-knitting. The big squares or rectangles are okay for at-home knitting, but clumsy for travel - so we fashioned one based on those a jeweler would use to size diamonds. The result is a joyous rainbow stack of connected discs for identifying knitting needle sizes US 0-15 / 2-10 mm.  The discs swivel out and click back together with tiny magnets (which makes it as much fun to play with as use) and the whole rainbow tool is small enough to pop into the Accessory Roll so you'll never leave home without it.