be quiet! Dark Base Pro 900 delivers unrivaled flexibility with impeccable cooling and silence features. It was designed for the enthusiasts and individualists - all of those, who expect the high standards, when it comes to modularity, compatibility and design for their workstations as well as overclocked and silent water-cooled systems. Dark Base Pro 900 has numerous modularity possibilities to satisfy every desire with lots of features to support special configurations. Aluminum surfaces and steel offer high stability with a look of extreme elegance. Simply an engineering work of art!