Function: 1. LOW NOISE: The DC speed regulator uses a synchronous rectification converter design, eliminating the need for a heatsink during high-current operation. It provides a clean DC output (no pulse) and a direct drive output design for low noise. 2. FANS within 12V 5A: This DC speed regulator supports all fans within 12V 5A, including brushed DC motors, water pumps, and light bulbs. Multiple fans can operate in parallel as long as they do not exceed the maximum current. 3. MANUAL SPEED CONTROL: The DC speed regulator's speed can be manually adjusted by turning the adjustable resistor on the board. 4. 4 TEMPERATURE ZONES: The DC speed regulator features 4 automatic temperature control zones with variable speed function, which activates automatically once the temperature control probe is connected. 5. VARIOUS SPEEDS: The DC speed regulator will operate at a low speed at the manually adjusted setting when temperature control is active. High speed is a direct 12V through, and speeds within the temperature zones change linearly. 6. WORKING MONITORING FUNCTION: The DC speed regulator includes a working monitoring function that supports a stop monitoring alarm with a speed line (like a three-wire fan), providing an audible and visual alarm if the speed drops below 450 rpm. Specification: Item Type: DC Speed Regulator Material: Plastic Working Parameters: 12V 5A Board Size: Approx. 50 x 48 mm / 2.0 x 1.9 in. Package List: 1 x DC Speed Regulator Note: Product includes Temperature Probe and Buzzer, no need to purchase separately.