Product Detail The innovative Barometric Ball Bearing technology provides longer life span while remaining lower noise level. PWM function for total performance solution at high and low speed operation. Removable blades for quick and easy cleaning. Nine massive sword-shaped blades generate outstanding high air pressure with balanced airflow. Triangular blade tips reduce turbulence at fan edges and decrease wind shear noise while keeping maximum sweeping area. . The "Cooler Master Excalibur 120mm PWM Case Fan - Barometric Ball Bearing R4-EXBB-20PK-R0" is best product for you. We recommended Cooler Master Excalibur 120mm PWM Case Fan - Barometric Ball Bearing R4-EXBB-20PK-R0