1. The working temperature range of the probe is about 45-50. Above this temperature, the fan automatically rotates and stops after the temperature to maintain temperature balance and reduce noise to increase fan life. Due to environmental and installation factors, there may be certain errors, please Pay attention 2. It is recommended to choose a fan with current consumption within 500mA to reduce the heat generated by the control board; 3. The input voltage should be as close as possible to the nominal voltage of the fan to get the best power utilization. If low voltage drive must be used, sufficient current supply must be ensured; 4. The fan speed is adjustable in 4 levels, which can take into account users' preferences for noise and efficiency. Product name Smart fan temperature controller Working voltage|DC: 5V-30VAC: 4V-20V Fan specifications|DC 12V less than equal 0.5A Product features 4-speed fan speed adjustable Starting temperature is about 45-50 Net weight is about 12 grams size:50x25x12mm Material:ABS colour:As shown Package Contents: 1 x Electronic thermostat Only the above package content, other products are not included. Note: Light 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.