This resistor box is designed specifically for electrical experimental teaching in middle schools, vocational colleges, and universities. It uses high-precision and high stability metal film resistors, and can be infinitely adjustable from 0 Ω to 9 999 999 Ω through a decimal dial or plug-in structure. It helps students intuitively grasp basic concepts such as Ohm's Law, series parallel connection, voltage division and current splitting, and bridge measurement. Typical experiment: Ohm's law verification; Measure unknown resistance using voltammetry; Bridge balance and error analysis; Demonstration of RC charging and discharging time constant; Research on the characteristics of voltage divider and current divider circuits.