Easy adjustment: You can adjust the voltage by simply turning the knob. Easy to install: Easy to install with volume mounting holes. Lower voltage adjustment: Adjusted to 15±5V at 50Hz. Trimmers can be adjusted at 60Hz Includes control contacts: Small capacity contacts allow the main circuit to be opened and closed Unique round heat dissipation space-saving and high efficiency. Applications: Temperature adjustment, lamp dimming, power adjustment, motor adjustment.