i have found myself changing nozzles on my printer almost every day or two and i easily lose track of which size nozzle is in my machine. i have an e3dv6 and the nozzles are dimpled for size but the cooked on plastic makes it hard to read and you cant see the back side to count them all. i made these to easily just clip on for a quick reference so i always know what is installed. these are printed in white esun petg and the numbers were just colored with a sharpie. these are setup to be printed at .5mm extrusion width and print in just a couple minutes. i made files for the most common nozzle sizes.