Features: 1.PRINCIPLE OPERATION: Slide rheostat resistance can be used to control the function of a circuit by changing its own resistance. 2.DUAL USE: The laboratory researching tool can be used as a constant/variable resistor to meet different circuit analysis needs. 3.APPLICATIONS: Sliding rheostat can be used as a current and voltage regulator for laboratory research and demonstration, as well as for excitation and speed control of power generation equipment and DC motors. 4.SAFETY AND RELIABILITY: The sliding head and insulated wiring hat are designed for safe and reliable use and are suitable for teaching physics and electricity. 5.DURABILITY: Alloy wire porcelain tube and contact copper sheet, exquisite workmanship, durability, and long service time. specification:Item Type: 2A 20 Slide Rheostat Resistance Material: Alloy Wire Porcelain Tube, Contact Copper Sheet Application Scenario: Physics Electricity Teaching, Circuit Analysis PackageList:1 x SlideRheostatResistance