Fangrui Product Details 1. 6v 12v 24v 28v 3a Speed Control Switch Pwm Dc Motor Speed Controller 2. Voltage Range: Dc 6v-28v 3. Current Range: Within 3a 4. Weight: About 22.6 G 5. Size: About 3.2 X 5 X 1.5 Cm 6. Precautions: 7. Please Make Sure The Power Supply Is Off Before Attempting To Wire The Controller 8. Connect The Dc Motor Governor To Dc Power Supply, Not Directly To Household 220v Ac Power Supply, Otherwise It Will Damage The Governor 9. Pay Attention To This Is Not A Power Module, Must Be Connected To The Motor In Order To Speed, Not Connected To The Motor Multimeter Output Did Not Change 10. Connect The Motor Can Not Be Divided Into Positive And Negative, When The Running Direction Is Inconsistent With The Expectation, You Can Adjust The Wire Sequence To Change The Direction 11. Do Not Connect The Positive And Negative Power Load Reversed, Which Will Damage The Controller