Features: 1. High?quality plastic material, hard, durable and corrosion?resistant, and also has long service life. 2. Small, light in weight, easy to install and operate, and can be used without complicated steps. 3. Wide temperature control range, temperature control range is ?50?110, control accuracy is 0.1. 4. Sophisticated production, provides stable performance, high work efficiency, can better meet your needs. 5. Comes with a high accuracy sensor, you don't need to buy a sensor seperately, saving your cost. Specification: High efficiency, high torque, low heat generating Control the speed of a DC motor with this controller With reverse polarity protection, high current protection color: #000000;">Input: 10V-30V -Output:Maximum 120W(When more than 24V) -PWM range: 5%-95% -Frequency: 500Hz -Current: Maximum 4A (Recommend you to use in 3A) -Size: < color: #000000;">74 * 47 * 28(mm) Operating Instruction: 1. Connect it to the power, ensure the positive inversion switch located in the middle of the zero, and connected with a DC power supply(the DC supply voltage range is more than 6V and less than 30V). Warning: do not reverse the positive and negative terminals of DC power source, otherwise regulator may be damaged. 2. Connect it to the motor, the motor line can be positive or negative, when the running direction is not consistent with the expectative one, you can adjust the sequence of lines or switch position to change the direction. 3. Adjust the switch. Positive inversion switch is used to control the motor speed direction. When the switch is located on the zero position, the motor stops rotating. 4.Adjust the potentiometer knob. Adjusting potentiometer knob can change output duty ratio of the regulator, then motor speed change. Package Included: 1pcs x DC Motor Speed Controller