It Is Made Of PC And Metal, And The Internal Conductor Is Pure Copper. It Is Durable And Can Be Used By You To Adjust The Output Voltage Between 50v-220v. Ultra-Low Voltage DC Motor Regulator With Speed Control Function. This Product Is Suitable For Self-Resetting Fuses. The Current Is Too Large And Will Automatically Disconnect. The Fuse Will Automatically Recover After Cooling. Pwm DC Motor Regulator Specifications: Maximum Output Power: 2000W Using The Latest Bidirectional High-Power Thyristor, The Current Is Adjusted To 25A, Which Is Very Convenient And Solves The Problem Of Overcurrent Caused By Too Small Resistance When The Electric Furnace Wire Is Cooled. The Product Is Accurate And Reliable, And Has Good Long-Term Stability. With Fixing Screw Holes, It Is Convenient To Install And Fix. Small Size, Low Power Consumption, And Fast Response. The Motor Controller Is Connected In Series To The Circuit Of Lights Or Other Electrical Appliances, And Then Turn The Knob To Adjust The Light, Instructions: Connect This Product In Series In The Circuit Of Desk Lamp Or Electrical Appliances, (. Disconnect Any One Of Live Wire Or Neutral Wire Of Desk Lamp, Electrical Appliances, Etc., And Connect The Two Wires Of This "Product") Rotate The Potentiometer The Rotary Rod Can Play The Role Of Light And Shade Adjustment, Speed Regulation, Pressure Regulation And Temperature Regulation; It Is Very Convenient To Use. This Product Is Suitable For: Using A New Type Of Bidirectional High-Power Thyristor, Because The Current Can Reach 25 Amps, Which Solves The Problem Of Overcurrent Caused By Too Small Resistance Of The Electric Furnace Wire When It Is Cooling; It Can Easily Adjust The Mains Power The Output Voltage Can Be Adjusted Arbitrarily Between 90----220 Volts For Use By Electrical Appliances. Such As: Electric Furnace, Water Heater Heat Adjustment, Light Adjustment Of Lamps, Small Motor Speed Adjustment, Electric Soldering Iron Temperature Adjustment, Etc. So As To Achieve The Effect Of Dimming, Temperature Regulation And Voltage Regulation. It Can Be Used By Large Electrical Appliances With A Power Consumption Of Less Than 2000 Watts. Because The Power Is Already Very Large, It Is Sufficient For General Household Appliances Or Small Factories. (The Inductive Or Capacitive Load Power Should Be Reduced. This Voltage Regulator Is Equipped With A Bidirectional High-Power Thyristor, And The Potentiometer Has A Nut. It Can Be Used Without Adding Any Components, Which Is Very Convenient And Practical). Color: As Shown Material: PC+metal Package Contents: 7 x Electronic Voltage Regulator Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.