You may consider several aspects when choosing a case fan uf 140 is one which has more features than you expect the special fan blade design with aacc technology airflow auto control channel optimize the airflow to be uniform dual ball bearing ensures the fan has a smooth rotation and long lifespan strong plastic frame with soft and elastic tpe cover to absorb operating vibration maximally special fan blade design to offer a unique visual effect when operating 2 ball bearing to offer s