Feature: 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 20Ω Slide Rheostat Resistance Material: Alloy Wire Porcelain Tube, Contact Copper Sheet Application Scenario: Physics Electricity Teaching, Circuit Analysis. Package List: 1 x Slide Rheostat Resistance