This is a handy reference for figuring out the value of your resistor. It is made of two diecut layers of stiff glossy paperboard. You rotate the layers until the first two colors of your resistor line up below the indicator line. These are the first two digits of your resistor value. Then you find the x10 multiplier, by locating the color of the 3rd band, on the top piece of the coder. That will show you how many 0’s to add after the first 2 numbers.
This is about 5″ wide.