1、The adjustable voltage range can be truly smooth and adjustable from 9V to 60V. 2、Wide application: Suitable for DC motors within 20A. 3、Durable Performance: Using high quality and delicate metal shell, no rust, safe and convenient to use. 4、High quality circuit board ensures stable and durable performance. 5、Easy to use: Easily control voltage and speed via the adjustable rotary knob. Description: This is a simple and easy-to-use DC motor speed controller with mini size, elegant appearance and stable performance. It is made with high quality circuit board which ensures a longer service life. The input voltage can be DC 9V to 60V and output voltage is 0-100% of the input voltage. This speed controller is quite convenient to use.   Features: The adjustable voltage range can be truly smooth and adjustable from 9V to 60V. Wide application: Suitable for DC motors within 20A. Durable Performance: Using high quality and delicate metal shell, no rust, safe and convenient to use. High quality circuit board ensures stable and durable performance. Easy to use: Easily control voltage and speed via the adjustable rotary knob. Specifications: Color: Silver Material: Metal Input Voltage: DC 9-60V Output Current: 0-20A Power: 1200W PWM Frequency: 25 KHz Adjustable Speed Range: 0-100% Speed Adjustment Way: Potentiometer Output Voltage: Linear under load Efficiency: >90% Size: Approx. 92 x 52 x 36mm / 3.6 x 2.0 x 1.4in Package Weight: 132g   Package List: 1 x Speed Controller   Note: This DC motor controller input is connected to direct current, CANNOT be connected to alternating current, or it will be burnt. Make sure the positive and negative polarity is connected correctly, otherwise the controller will be damaged.