This is a handy resistor colour code “calculator” that doesn’t need power supply or to be installed on a PC. As you know most resistors use coloured bands in order to show their value. So basically ...

Thanks to reader Alan Metcalfe for bringing this to Gadget Master's attention. He describes it as "a simple Mr Spock circular (resistor) calculator, to cut-out and make". The Resistor Code Calculator ...