Fangrui Product Details : Function: Pulse Width Modulation(pwm) Is Used To Make The Speed More Stable, And The Strength Is High At Low Speed. Notice: This Is A Dc Brush Motor Controller, So Please Dont Use It On Ac Motors. Wide Use: The Speed Controller Is Widely Used In Industrial Dc Motor Speed Regulation, Dc Fan, Etc. Easy To Use: Adopt The Motor Of Speed Control Mode, It Has Stable Performance, The Speed Can Be Adjusted And It Is Easy To Install. Specification: Brand New Supply Voltage: Dc 9v-60v Installation Method: Panel Type, And Wiring According To Wiring Diagram Colour: Black Material: Metal + Plastic Size: Approx. 99*60*90mm Package Contents: 1* 10a Pwm Motor Speed Controller 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.