GOOD DESIGN: It integrates manual speed regulation and automatic temperature control and speed regulation function. SAFETY: When the corresponding open channel fan break down, the controller will alarm with sound and light (works with buzzle), alarm will automatically eliminated when the fan is rotated recovery. USAGE: Accurate temperature setting and precise control. The controller only controls the speed of the all standard four-wire chassis fan and CPU fan for NOTE: When the temperature lower than the accelerated temperature, then output at the minimum rotation speed; when it exceed over the full temperature, then always output at full speed. SATISFACTION GUARANTEE: We care for every customers feeling.If this product does not meet or exceed your expectations,please send it back for a refund no questions asked.