Excalibur, as the name suggests, is inspired by the legendary sword of King Arthur from the middle ages. The nine massive sword-shaped blades are designed to produce exceptionally high air pressure, which fortify the cooling efficiency when used in dense water cooling radiators or performance heatsinks. This is the first fan from Cooler Master to adopt Barometric Ball Bearing (BBB) technology. Bearing Type: Barometric Ball RPM: 600 - 2000 RPM±10% Air Flow: 26.4 - 85.6 CFM±10% Noise Level: 13 - 30 dBA Power Connector: 4 Pin Color: Black Compatibility: Case Dimensions: 120 x 120 x 25mm