1. Builtin switch: The builtin switch of the motor speed controller allows you to control the forward/reverse direction and stop functions of the DC motor directly on the switch. 2. PWM Speed Control: The 1203BB DC motor speed controller regulates motor speed by adjusting pulse width modulation (PWM). 3. Safe: The circuit features a builtin 3A fuse for safer operation of the DC motor speed controller. 4. Applications: This DC motor speed controller is suitable for speed regulation in DC motors, fans, fish tank oxygen pumps, and similar products. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.