Features: brand new and high quality. With stepless speed control knob, it can be adjusted or closed. Adjustment range: 25%- (can be switched off). The use of pure copper thickened wire is safer and more stable. It is used for light bulb dimming, aeration pump to adjust air volume, water pump to adjust water volume, fan to adjust wind speed, heating plate to adjust heat, equipment to adjust power, motor to adjust speed and so on. Specifications: Material: Electronic Component Weight: 15g Size: 50x19x23mm/1.97x0.75x0.91inch Color: Black Working Voltage: 10-14V Control Current: 1-4A Adjustment Range: 25%-100% Rated Current: 4A Package Includes: 1x Speed Controller note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.