Features: brand new and high quality It is not only to use DC motor controls of the speed, but also to use for adjust the LED light. DC motor governor input is DC, can not directly connected to the AC (for example: home 220V AC), otherwise it will burn! Do not reverse DC power supply positive and negative terminals, otherwise the governor may be damaged. The motor can be positive or negative, when the direction of operation and expectations does not match, you can adjust the line order to change the direction. Adjust the potentiometer knob to change the governor output duty cycle, the motor speed changes. Specifications: Operating voltage: DC4.5V-35V Output current: 0-5A Output power: 90W (max) Quiescent current: 7uA (standby) PWM frequency: 20khz Size: approx 30mm x 26mm x 14mm/1.18x1.02x0.55in (Without Handle) Package Includes: 1PCx DC Motor Speed Controller Module note: Due to the problems of lighting effects and shooting angles, there will be certain tolerances in the product, please understand. Please allow 0-1cm error due to the manual measurment.