Abstract: An air duct includes a main body, and an adjusting assembly. The main body includes a top plate and two lateral plates extending from opposite sides of the top plate. The adjusting assembly includes two first limiting plates, a second limiting plate, and a third plate. The second and third limiting plates are slidably attached to each other, and are respectively pivotably attached to the first limiting plates. Each first limiting plate is adjustably attached to the lateral plates.

Abstract: An air duct includes a main body, and an adjusting assembly. The main body includes a top plate and two lateral plates extending from opposite sides of the top plate. The adjusting assembly includes two first limiting plates, a second limiting plate, and a third plate. The second and third limiting plates are slidably attached to each other, and are respectively pivotably attached to the first limiting plates. Each first limiting plate is adjustably attached to the lateral plates.

Abstract: A hard disk drive holder includes main body, spindle slidably mounted to the main body, handle rotatably connected to the main body via the spindle, and hook slidably mounted to the main body. The handle includes claw and locking tongue. The handle rotates between closed and opened positions. When the handle is at closed position, if the spindle slides from a first position to a second position, the locking tongue gradually extends out of the main body. When the handle rotates to closed position, if the spindle isn't at first position, the claw engages with a blocking piece of the hook and compels the hook to slide from a third position towards a fourth position until the claw goes over the blocking piece. A first spring biases the spindle to second position. A second spring biases the handle to opened position. A third spring biases the hook to third position.